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* [PATCH v8 01/12] clk: pwm: Use 64-bit division function
       [not found] <cover.1583889178.git.gurus@codeaurora.org>
@ 2020-03-11  1:41 ` Guru Das Srinagesh
  2020-03-11 16:58   ` David Laight
  2020-03-11  1:41 ` [PATCH v8 02/12] drm/i915: Use 64-bit division macro Guru Das Srinagesh
                   ` (10 subsequent siblings)
  11 siblings, 1 reply; 22+ messages in thread
From: Guru Das Srinagesh @ 2020-03-11  1:41 UTC (permalink / raw)
  To: linux-pwm
  Cc: Thierry Reding, Uwe Kleine-König, Subbaraman Narayanamurthy,
	linux-kernel, Guru Das Srinagesh, Michael Turquette,
	Stephen Boyd, linux-clk

Since the PWM framework is switching struct pwm_args.period's datatype
to u64, prepare for this transition by using div64_u64 to handle a
64-bit divisor.

Cc: Michael Turquette <mturquette@baylibre.com>
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: linux-clk@vger.kernel.org

Signed-off-by: Guru Das Srinagesh <gurus@codeaurora.org>
---
 drivers/clk/clk-pwm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/clk/clk-pwm.c b/drivers/clk/clk-pwm.c
index 87fe0b0e..7b1f7a0 100644
--- a/drivers/clk/clk-pwm.c
+++ b/drivers/clk/clk-pwm.c
@@ -89,7 +89,7 @@ static int clk_pwm_probe(struct platform_device *pdev)
 	}
 
 	if (of_property_read_u32(node, "clock-frequency", &clk_pwm->fixed_rate))
-		clk_pwm->fixed_rate = NSEC_PER_SEC / pargs.period;
+		clk_pwm->fixed_rate = div64_u64(NSEC_PER_SEC, pargs.period);
 
 	if (pargs.period != NSEC_PER_SEC / clk_pwm->fixed_rate &&
 	    pargs.period != DIV_ROUND_UP(NSEC_PER_SEC, clk_pwm->fixed_rate)) {
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project


^ permalink raw reply	[flat|nested] 22+ messages in thread

* [PATCH v8 02/12] drm/i915: Use 64-bit division macro
       [not found] <cover.1583889178.git.gurus@codeaurora.org>
  2020-03-11  1:41 ` [PATCH v8 01/12] clk: pwm: Use 64-bit division function Guru Das Srinagesh
@ 2020-03-11  1:41 ` Guru Das Srinagesh
  2020-03-11  1:41 ` [PATCH v8 03/12] hwmon: pwm-fan: " Guru Das Srinagesh
                   ` (9 subsequent siblings)
  11 siblings, 0 replies; 22+ messages in thread
From: Guru Das Srinagesh @ 2020-03-11  1:41 UTC (permalink / raw)
  To: linux-pwm
  Cc: Thierry Reding, Uwe Kleine-König, Subbaraman Narayanamurthy,
	linux-kernel, Guru Das Srinagesh, Jani Nikula, Joonas Lahtinen,
	David Airlie, Daniel Vetter, Chris Wilson,
	Ville Syrjälä,
	intel-gfx, dri-devel

Since the PWM framework is switching struct pwm_state.duty_cycle's
datatype to u64, prepare for this transition by using DIV_ROUND_UP_ULL
to handle a 64-bit dividend.

Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: "Ville Syrjälä" <ville.syrjala@linux.intel.com>
Cc: intel-gfx@lists.freedesktop.org
Cc: dri-devel@lists.freedesktop.org

Signed-off-by: Guru Das Srinagesh <gurus@codeaurora.org>
---
 drivers/gpu/drm/i915/display/intel_panel.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/display/intel_panel.c b/drivers/gpu/drm/i915/display/intel_panel.c
index bc14e9c..843cac1 100644
--- a/drivers/gpu/drm/i915/display/intel_panel.c
+++ b/drivers/gpu/drm/i915/display/intel_panel.c
@@ -1868,7 +1868,7 @@ static int pwm_setup_backlight(struct intel_connector *connector,
 
 	panel->backlight.min = 0; /* 0% */
 	panel->backlight.max = 100; /* 100% */
-	panel->backlight.level = DIV_ROUND_UP(
+	panel->backlight.level = DIV_ROUND_UP_ULL(
 				 pwm_get_duty_cycle(panel->backlight.pwm) * 100,
 				 CRC_PMIC_PWM_PERIOD_NS);
 	panel->backlight.enabled = panel->backlight.level != 0;
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project


^ permalink raw reply	[flat|nested] 22+ messages in thread

* [PATCH v8 03/12] hwmon: pwm-fan: Use 64-bit division macro
       [not found] <cover.1583889178.git.gurus@codeaurora.org>
  2020-03-11  1:41 ` [PATCH v8 01/12] clk: pwm: Use 64-bit division function Guru Das Srinagesh
  2020-03-11  1:41 ` [PATCH v8 02/12] drm/i915: Use 64-bit division macro Guru Das Srinagesh
@ 2020-03-11  1:41 ` Guru Das Srinagesh
  2020-03-11 15:08   ` Guenter Roeck
  2020-03-11  1:41 ` [PATCH v8 04/12] ir-rx51: " Guru Das Srinagesh
                   ` (8 subsequent siblings)
  11 siblings, 1 reply; 22+ messages in thread
From: Guru Das Srinagesh @ 2020-03-11  1:41 UTC (permalink / raw)
  To: linux-pwm
  Cc: Thierry Reding, Uwe Kleine-König, Subbaraman Narayanamurthy,
	linux-kernel, Guru Das Srinagesh, Kamil Debski,
	Bartlomiej Zolnierkiewicz, Jean Delvare, Guenter Roeck,
	Liam Girdwood, Mark Brown, linux-hwmon

Since the PWM framework is switching struct pwm_args.period's datatype
to u64, prepare for this transition by using DIV_ROUND_UP_ULL to handle
a 64-bit dividend.

Cc: Kamil Debski <kamil@wypas.org>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Jean Delvare <jdelvare@suse.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: linux-hwmon@vger.kernel.org

Signed-off-by: Guru Das Srinagesh <gurus@codeaurora.org>
---
 drivers/hwmon/pwm-fan.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c
index 42ffd2e..283423a 100644
--- a/drivers/hwmon/pwm-fan.c
+++ b/drivers/hwmon/pwm-fan.c
@@ -437,7 +437,7 @@ static int pwm_fan_resume(struct device *dev)
 		return 0;
 
 	pwm_get_args(ctx->pwm, &pargs);
-	duty = DIV_ROUND_UP(ctx->pwm_value * (pargs.period - 1), MAX_PWM);
+	duty = DIV_ROUND_UP_ULL(ctx->pwm_value * (pargs.period - 1), MAX_PWM);
 	ret = pwm_config(ctx->pwm, duty, pargs.period);
 	if (ret)
 		return ret;
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project


^ permalink raw reply	[flat|nested] 22+ messages in thread

* [PATCH v8 04/12] ir-rx51: Use 64-bit division macro
       [not found] <cover.1583889178.git.gurus@codeaurora.org>
                   ` (2 preceding siblings ...)
  2020-03-11  1:41 ` [PATCH v8 03/12] hwmon: pwm-fan: " Guru Das Srinagesh
@ 2020-03-11  1:41 ` Guru Das Srinagesh
  2020-03-11  2:11   ` Sean Young
  2020-03-11  1:41 ` [PATCH v8 05/12] pwm: clps711x: " Guru Das Srinagesh
                   ` (7 subsequent siblings)
  11 siblings, 1 reply; 22+ messages in thread
From: Guru Das Srinagesh @ 2020-03-11  1:41 UTC (permalink / raw)
  To: linux-pwm
  Cc: Thierry Reding, Uwe Kleine-König, Subbaraman Narayanamurthy,
	linux-kernel, Guru Das Srinagesh, Mauro Carvalho Chehab,
	Richard Fontana, Thomas Gleixner, Kate Stewart, Allison Randal,
	linux-media

Since the PWM framework is switching struct pwm_state.period's datatype
to u64, prepare for this transition by using DIV_ROUND_CLOSEST_ULL to
handle a 64-bit dividend.

Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Richard Fontana <rfontana@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Allison Randal <allison@lohutok.net>
Cc: linux-media@vger.kernel.org

Signed-off-by: Guru Das Srinagesh <gurus@codeaurora.org>
---
 drivers/media/rc/ir-rx51.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/media/rc/ir-rx51.c b/drivers/media/rc/ir-rx51.c
index 8574eda..9a5dfd7 100644
--- a/drivers/media/rc/ir-rx51.c
+++ b/drivers/media/rc/ir-rx51.c
@@ -241,7 +241,8 @@ static int ir_rx51_probe(struct platform_device *dev)
 	}
 
 	/* Use default, in case userspace does not set the carrier */
-	ir_rx51.freq = DIV_ROUND_CLOSEST(pwm_get_period(pwm), NSEC_PER_SEC);
+	ir_rx51.freq = DIV_ROUND_CLOSEST_ULL(pwm_get_period(pwm),
+			NSEC_PER_SEC);
 	pwm_put(pwm);
 
 	hrtimer_init(&ir_rx51.timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project


^ permalink raw reply	[flat|nested] 22+ messages in thread

* [PATCH v8 05/12] pwm: clps711x: Use 64-bit division macro
       [not found] <cover.1583889178.git.gurus@codeaurora.org>
                   ` (3 preceding siblings ...)
  2020-03-11  1:41 ` [PATCH v8 04/12] ir-rx51: " Guru Das Srinagesh
@ 2020-03-11  1:41 ` Guru Das Srinagesh
  2020-03-11  1:41 ` [PATCH v8 06/12] pwm: pwm-imx-tpm: " Guru Das Srinagesh
                   ` (6 subsequent siblings)
  11 siblings, 0 replies; 22+ messages in thread
From: Guru Das Srinagesh @ 2020-03-11  1:41 UTC (permalink / raw)
  To: linux-pwm
  Cc: Thierry Reding, Uwe Kleine-König, Subbaraman Narayanamurthy,
	linux-kernel, Guru Das Srinagesh, Alexander Shiyan

Since the PWM framework is switching struct pwm_args.period's datatype
to u64, prepare for this transition by using DIV64_U64_ROUND_CLOSEST to
handle a 64-bit divisor.

Cc: Alexander Shiyan <shc_work@mail.ru>

Signed-off-by: Guru Das Srinagesh <gurus@codeaurora.org>
---
 drivers/pwm/pwm-clps711x.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pwm/pwm-clps711x.c b/drivers/pwm/pwm-clps711x.c
index 924d39a..ba9500a 100644
--- a/drivers/pwm/pwm-clps711x.c
+++ b/drivers/pwm/pwm-clps711x.c
@@ -43,7 +43,7 @@ static void clps711x_pwm_update_val(struct clps711x_chip *priv, u32 n, u32 v)
 static unsigned int clps711x_get_duty(struct pwm_device *pwm, unsigned int v)
 {
 	/* Duty cycle 0..15 max */
-	return DIV_ROUND_CLOSEST(v * 0xf, pwm->args.period);
+	return DIV64_U64_ROUND_CLOSEST(v * 0xf, pwm->args.period);
 }
 
 static int clps711x_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project


^ permalink raw reply	[flat|nested] 22+ messages in thread

* [PATCH v8 06/12] pwm: pwm-imx-tpm: Use 64-bit division macro
       [not found] <cover.1583889178.git.gurus@codeaurora.org>
                   ` (4 preceding siblings ...)
  2020-03-11  1:41 ` [PATCH v8 05/12] pwm: clps711x: " Guru Das Srinagesh
@ 2020-03-11  1:41 ` Guru Das Srinagesh
  2020-03-11  1:41 ` [PATCH v8 07/12] pwm: imx27: Use 64-bit division macro and function Guru Das Srinagesh
                   ` (5 subsequent siblings)
  11 siblings, 0 replies; 22+ messages in thread
From: Guru Das Srinagesh @ 2020-03-11  1:41 UTC (permalink / raw)
  To: linux-pwm
  Cc: Thierry Reding, Uwe Kleine-König, Subbaraman Narayanamurthy,
	linux-kernel, Guru Das Srinagesh, Shawn Guo, Sascha Hauer,
	Pengutronix Kernel Team, Fabio Estevam, NXP Linux Team

Since the PWM framework is switching struct pwm_state.period's datatype
to u64, prepare for this transition by using DIV64_U64_ROUND_CLOSEST to
handle a 64-bit divisor.

Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: NXP Linux Team <linux-imx@nxp.com>

Signed-off-by: Guru Das Srinagesh <gurus@codeaurora.org>
---
 drivers/pwm/pwm-imx-tpm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pwm/pwm-imx-tpm.c b/drivers/pwm/pwm-imx-tpm.c
index 9145f61..53bf364 100644
--- a/drivers/pwm/pwm-imx-tpm.c
+++ b/drivers/pwm/pwm-imx-tpm.c
@@ -126,7 +126,7 @@ static int pwm_imx_tpm_round_state(struct pwm_chip *chip,
 		real_state->duty_cycle = state->duty_cycle;
 
 	tmp = (u64)p->mod * real_state->duty_cycle;
-	p->val = DIV_ROUND_CLOSEST_ULL(tmp, real_state->period);
+	p->val = DIV64_U64_ROUND_CLOSEST(tmp, real_state->period);
 
 	real_state->polarity = state->polarity;
 	real_state->enabled = state->enabled;
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project


^ permalink raw reply	[flat|nested] 22+ messages in thread

* [PATCH v8 07/12] pwm: imx27: Use 64-bit division macro and function
       [not found] <cover.1583889178.git.gurus@codeaurora.org>
                   ` (5 preceding siblings ...)
  2020-03-11  1:41 ` [PATCH v8 06/12] pwm: pwm-imx-tpm: " Guru Das Srinagesh
@ 2020-03-11  1:41 ` Guru Das Srinagesh
  2020-03-11  1:41 ` [PATCH v8 08/12] pwm: sifive: Use 64-bit division macro Guru Das Srinagesh
                   ` (4 subsequent siblings)
  11 siblings, 0 replies; 22+ messages in thread
From: Guru Das Srinagesh @ 2020-03-11  1:41 UTC (permalink / raw)
  To: linux-pwm
  Cc: Thierry Reding, Uwe Kleine-König, Subbaraman Narayanamurthy,
	linux-kernel, Guru Das Srinagesh, Shawn Guo, Sascha Hauer,
	Pengutronix Kernel Team, Fabio Estevam, NXP Linux Team

Since the PWM framework is switching struct pwm_state.period's
datatype to u64, prepare for this transition by using
DIV_ROUND_UP_ULL to handle a 64-bit dividend, and div64_u64 to handle a
64-bit divisor.

Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: NXP Linux Team <linux-imx@nxp.com>

Signed-off-by: Guru Das Srinagesh <gurus@codeaurora.org>
---
 drivers/pwm/pwm-imx27.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/pwm/pwm-imx27.c b/drivers/pwm/pwm-imx27.c
index 35a7ac42..b7d38d0 100644
--- a/drivers/pwm/pwm-imx27.c
+++ b/drivers/pwm/pwm-imx27.c
@@ -208,7 +208,7 @@ static void pwm_imx27_wait_fifo_slot(struct pwm_chip *chip,
 	sr = readl(imx->mmio_base + MX3_PWMSR);
 	fifoav = FIELD_GET(MX3_PWMSR_FIFOAV, sr);
 	if (fifoav == MX3_PWMSR_FIFOAV_4WORDS) {
-		period_ms = DIV_ROUND_UP(pwm_get_period(pwm),
+		period_ms = DIV_ROUND_UP_ULL(pwm_get_period(pwm),
 					 NSEC_PER_MSEC);
 		msleep(period_ms);
 
@@ -240,8 +240,7 @@ static int pwm_imx27_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 
 	period_cycles /= prescale;
 	c = (unsigned long long)period_cycles * state->duty_cycle;
-	do_div(c, state->period);
-	duty_cycles = c;
+	duty_cycles = div64_u64(c, state->period);
 
 	/*
 	 * according to imx pwm RM, the real period value should be PERIOD
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project


^ permalink raw reply	[flat|nested] 22+ messages in thread

* [PATCH v8 08/12] pwm: sifive: Use 64-bit division macro
       [not found] <cover.1583889178.git.gurus@codeaurora.org>
                   ` (6 preceding siblings ...)
  2020-03-11  1:41 ` [PATCH v8 07/12] pwm: imx27: Use 64-bit division macro and function Guru Das Srinagesh
@ 2020-03-11  1:41 ` Guru Das Srinagesh
  2020-03-11  1:41 ` [PATCH v8 09/12] pwm: stm32-lp: Use %llu format specifier for period Guru Das Srinagesh
                   ` (3 subsequent siblings)
  11 siblings, 0 replies; 22+ messages in thread
From: Guru Das Srinagesh @ 2020-03-11  1:41 UTC (permalink / raw)
  To: linux-pwm
  Cc: Thierry Reding, Uwe Kleine-König, Subbaraman Narayanamurthy,
	linux-kernel, Guru Das Srinagesh, Palmer Dabbelt, Paul Walmsley,
	linux-riscv, Yash Shah, Atish Patra

Since the PWM framework is switching struct pwm_args.period's datatype
to u64, prepare for this transition by using DIV64_U64_ROUND_CLOSEST to
handle a 64-bit divisor.

Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: linux-riscv@lists.infradead.org
Cc: Yash Shah <yash.shah@sifive.com>
Cc: Atish Patra <atish.patra@wdc.com>

Signed-off-by: Guru Das Srinagesh <gurus@codeaurora.org>
---
 drivers/pwm/pwm-sifive.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pwm/pwm-sifive.c b/drivers/pwm/pwm-sifive.c
index cc63f9b..62de0bb 100644
--- a/drivers/pwm/pwm-sifive.c
+++ b/drivers/pwm/pwm-sifive.c
@@ -181,7 +181,7 @@ static int pwm_sifive_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 	 * consecutively
 	 */
 	num = (u64)duty_cycle * (1U << PWM_SIFIVE_CMPWIDTH);
-	frac = DIV_ROUND_CLOSEST_ULL(num, state->period);
+	frac = DIV64_U64_ROUND_CLOSEST(num, state->period);
 	/* The hardware cannot generate a 100% duty cycle */
 	frac = min(frac, (1U << PWM_SIFIVE_CMPWIDTH) - 1);
 
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project


^ permalink raw reply	[flat|nested] 22+ messages in thread

* [PATCH v8 09/12] pwm: stm32-lp: Use %llu format specifier for period
       [not found] <cover.1583889178.git.gurus@codeaurora.org>
                   ` (7 preceding siblings ...)
  2020-03-11  1:41 ` [PATCH v8 08/12] pwm: sifive: Use 64-bit division macro Guru Das Srinagesh
@ 2020-03-11  1:41 ` Guru Das Srinagesh
  2020-03-11  1:41 ` [PATCH v8 10/12] pwm: sun4i: Use 64-bit division function Guru Das Srinagesh
                   ` (2 subsequent siblings)
  11 siblings, 0 replies; 22+ messages in thread
From: Guru Das Srinagesh @ 2020-03-11  1:41 UTC (permalink / raw)
  To: linux-pwm
  Cc: Thierry Reding, Uwe Kleine-König, Subbaraman Narayanamurthy,
	linux-kernel, Guru Das Srinagesh, Fabrice Gasnier,
	Maxime Coquelin, Alexandre Torgue

Since the PWM framework is switching struct pwm_args.period's
datatype to u64, prepare for this transition by using the right
specifier for printing a 64-bit value.

Cc: Fabrice Gasnier <fabrice.gasnier@st.com>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Alexandre Torgue <alexandre.torgue@st.com>

Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Guru Das Srinagesh <gurus@codeaurora.org>
---
 drivers/pwm/pwm-stm32-lp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pwm/pwm-stm32-lp.c b/drivers/pwm/pwm-stm32-lp.c
index 67fca62..134c146 100644
--- a/drivers/pwm/pwm-stm32-lp.c
+++ b/drivers/pwm/pwm-stm32-lp.c
@@ -61,7 +61,7 @@ static int stm32_pwm_lp_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 	do_div(div, NSEC_PER_SEC);
 	if (!div) {
 		/* Clock is too slow to achieve requested period. */
-		dev_dbg(priv->chip.dev, "Can't reach %u ns\n",	state->period);
+		dev_dbg(priv->chip.dev, "Can't reach %llu ns\n", state->period);
 		return -EINVAL;
 	}
 
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project


^ permalink raw reply	[flat|nested] 22+ messages in thread

* [PATCH v8 10/12] pwm: sun4i: Use 64-bit division function
       [not found] <cover.1583889178.git.gurus@codeaurora.org>
                   ` (8 preceding siblings ...)
  2020-03-11  1:41 ` [PATCH v8 09/12] pwm: stm32-lp: Use %llu format specifier for period Guru Das Srinagesh
@ 2020-03-11  1:41 ` Guru Das Srinagesh
  2020-03-11  3:35   ` Chen-Yu Tsai
  2020-03-11  1:41 ` [PATCH v8 11/12] backlight: pwm_bl: " Guru Das Srinagesh
  2020-03-11  1:41 ` [PATCH v8 12/12] pwm: core: Convert period and duty cycle to u64 Guru Das Srinagesh
  11 siblings, 1 reply; 22+ messages in thread
From: Guru Das Srinagesh @ 2020-03-11  1:41 UTC (permalink / raw)
  To: linux-pwm
  Cc: Thierry Reding, Uwe Kleine-König, Subbaraman Narayanamurthy,
	linux-kernel, Guru Das Srinagesh, Maxime Ripard, Chen-Yu Tsai,
	Philipp Zabel

Since the PWM framework is switching struct pwm_state.period's datatype
to u64, prepare for this transition by using div_u64 to handle a 64-bit
dividend instead of a straight division operation.

Cc: Maxime Ripard <mripard@kernel.org>
Cc: Chen-Yu Tsai <wens@csie.org>
Cc: Philipp Zabel <p.zabel@pengutronix.de>

Signed-off-by: Guru Das Srinagesh <gurus@codeaurora.org>
---
 drivers/pwm/pwm-sun4i.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pwm/pwm-sun4i.c b/drivers/pwm/pwm-sun4i.c
index 3e3efa6..772fdf4 100644
--- a/drivers/pwm/pwm-sun4i.c
+++ b/drivers/pwm/pwm-sun4i.c
@@ -286,7 +286,7 @@ static int sun4i_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 	val = (duty & PWM_DTY_MASK) | PWM_PRD(period);
 	sun4i_pwm_writel(sun4i_pwm, val, PWM_CH_PRD(pwm->hwpwm));
 	sun4i_pwm->next_period[pwm->hwpwm] = jiffies +
-		usecs_to_jiffies(cstate.period / 1000 + 1);
+		usecs_to_jiffies(div_u64(cstate.period, 1000) + 1);
 	sun4i_pwm->needs_delay[pwm->hwpwm] = true;
 
 	if (state->polarity != PWM_POLARITY_NORMAL)
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project


^ permalink raw reply	[flat|nested] 22+ messages in thread

* [PATCH v8 11/12] backlight: pwm_bl: Use 64-bit division function
       [not found] <cover.1583889178.git.gurus@codeaurora.org>
                   ` (9 preceding siblings ...)
  2020-03-11  1:41 ` [PATCH v8 10/12] pwm: sun4i: Use 64-bit division function Guru Das Srinagesh
@ 2020-03-11  1:41 ` Guru Das Srinagesh
  2020-03-11 10:05   ` Daniel Thompson
  2020-03-11  1:41 ` [PATCH v8 12/12] pwm: core: Convert period and duty cycle to u64 Guru Das Srinagesh
  11 siblings, 1 reply; 22+ messages in thread
From: Guru Das Srinagesh @ 2020-03-11  1:41 UTC (permalink / raw)
  To: linux-pwm
  Cc: Thierry Reding, Uwe Kleine-König, Subbaraman Narayanamurthy,
	linux-kernel, Guru Das Srinagesh, Lee Jones, Daniel Thompson,
	Jingoo Han, Bartlomiej Zolnierkiewicz, dri-devel, linux-fbdev

Since the PWM framework is switching struct pwm_state.period's datatype
to u64, prepare for this transition by using div_u64 to handle a 64-bit
dividend instead of a straight division operation.

Cc: Lee Jones <lee.jones@linaro.org>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Jingoo Han <jingoohan1@gmail.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: linux-pwm@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: linux-fbdev@vger.kernel.org

Signed-off-by: Guru Das Srinagesh <gurus@codeaurora.org>
---
 drivers/video/backlight/pwm_bl.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
index efb4efc..3e5dbcf 100644
--- a/drivers/video/backlight/pwm_bl.c
+++ b/drivers/video/backlight/pwm_bl.c
@@ -625,7 +625,8 @@ static int pwm_backlight_probe(struct platform_device *pdev)
 		pb->scale = data->max_brightness;
 	}
 
-	pb->lth_brightness = data->lth_brightness * (state.period / pb->scale);
+	pb->lth_brightness = data->lth_brightness * (div_u64(state.period,
+				pb->scale));
 
 	props.type = BACKLIGHT_RAW;
 	props.max_brightness = data->max_brightness;
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project


^ permalink raw reply	[flat|nested] 22+ messages in thread

* [PATCH v8 12/12] pwm: core: Convert period and duty cycle to u64
       [not found] <cover.1583889178.git.gurus@codeaurora.org>
                   ` (10 preceding siblings ...)
  2020-03-11  1:41 ` [PATCH v8 11/12] backlight: pwm_bl: " Guru Das Srinagesh
@ 2020-03-11  1:41 ` Guru Das Srinagesh
  11 siblings, 0 replies; 22+ messages in thread
From: Guru Das Srinagesh @ 2020-03-11  1:41 UTC (permalink / raw)
  To: linux-pwm
  Cc: Thierry Reding, Uwe Kleine-König, Subbaraman Narayanamurthy,
	linux-kernel, Guru Das Srinagesh

Because period and duty cycle are defined as ints with units of
nanoseconds, the maximum time duration that can be set is limited to
~2.147 seconds. Change their definitions to u64 in the structs of the
PWM framework so that higher durations may be set.

Signed-off-by: Guru Das Srinagesh <gurus@codeaurora.org>
---
 drivers/pwm/core.c  |  4 ++--
 drivers/pwm/sysfs.c |  8 ++++----
 include/linux/pwm.h | 12 ++++++------
 3 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index 5a7f659..81aa3c2 100644
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -1163,8 +1163,8 @@ static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s)
 		if (state.enabled)
 			seq_puts(s, " enabled");
 
-		seq_printf(s, " period: %u ns", state.period);
-		seq_printf(s, " duty: %u ns", state.duty_cycle);
+		seq_printf(s, " period: %llu ns", state.period);
+		seq_printf(s, " duty: %llu ns", state.duty_cycle);
 		seq_printf(s, " polarity: %s",
 			   state.polarity ? "inverse" : "normal");
 
diff --git a/drivers/pwm/sysfs.c b/drivers/pwm/sysfs.c
index 2389b86..449dbc0 100644
--- a/drivers/pwm/sysfs.c
+++ b/drivers/pwm/sysfs.c
@@ -42,7 +42,7 @@ static ssize_t period_show(struct device *child,
 
 	pwm_get_state(pwm, &state);
 
-	return sprintf(buf, "%u\n", state.period);
+	return sprintf(buf, "%llu\n", state.period);
 }
 
 static ssize_t period_store(struct device *child,
@@ -52,10 +52,10 @@ static ssize_t period_store(struct device *child,
 	struct pwm_export *export = child_to_pwm_export(child);
 	struct pwm_device *pwm = export->pwm;
 	struct pwm_state state;
-	unsigned int val;
+	u64 val;
 	int ret;
 
-	ret = kstrtouint(buf, 0, &val);
+	ret = kstrtou64(buf, 0, &val);
 	if (ret)
 		return ret;
 
@@ -77,7 +77,7 @@ static ssize_t duty_cycle_show(struct device *child,
 
 	pwm_get_state(pwm, &state);
 
-	return sprintf(buf, "%u\n", state.duty_cycle);
+	return sprintf(buf, "%llu\n", state.duty_cycle);
 }
 
 static ssize_t duty_cycle_store(struct device *child,
diff --git a/include/linux/pwm.h b/include/linux/pwm.h
index 0ef808d..b53f13d 100644
--- a/include/linux/pwm.h
+++ b/include/linux/pwm.h
@@ -39,7 +39,7 @@ enum pwm_polarity {
  * current PWM hardware state.
  */
 struct pwm_args {
-	unsigned int period;
+	u64 period;
 	enum pwm_polarity polarity;
 };
 
@@ -56,8 +56,8 @@ enum {
  * @enabled: PWM enabled status
  */
 struct pwm_state {
-	unsigned int period;
-	unsigned int duty_cycle;
+	u64 period;
+	u64 duty_cycle;
 	enum pwm_polarity polarity;
 	bool enabled;
 };
@@ -105,13 +105,13 @@ static inline bool pwm_is_enabled(const struct pwm_device *pwm)
 	return state.enabled;
 }
 
-static inline void pwm_set_period(struct pwm_device *pwm, unsigned int period)
+static inline void pwm_set_period(struct pwm_device *pwm, u64 period)
 {
 	if (pwm)
 		pwm->state.period = period;
 }
 
-static inline unsigned int pwm_get_period(const struct pwm_device *pwm)
+static inline u64 pwm_get_period(const struct pwm_device *pwm)
 {
 	struct pwm_state state;
 
@@ -126,7 +126,7 @@ static inline void pwm_set_duty_cycle(struct pwm_device *pwm, unsigned int duty)
 		pwm->state.duty_cycle = duty;
 }
 
-static inline unsigned int pwm_get_duty_cycle(const struct pwm_device *pwm)
+static inline u64 pwm_get_duty_cycle(const struct pwm_device *pwm)
 {
 	struct pwm_state state;
 
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project


^ permalink raw reply	[flat|nested] 22+ messages in thread

* Re: [PATCH v8 04/12] ir-rx51: Use 64-bit division macro
  2020-03-11  1:41 ` [PATCH v8 04/12] ir-rx51: " Guru Das Srinagesh
@ 2020-03-11  2:11   ` Sean Young
  0 siblings, 0 replies; 22+ messages in thread
From: Sean Young @ 2020-03-11  2:11 UTC (permalink / raw)
  To: Guru Das Srinagesh
  Cc: linux-pwm, Thierry Reding, Uwe Kleine-König,
	Subbaraman Narayanamurthy, linux-kernel, Mauro Carvalho Chehab,
	Richard Fontana, Thomas Gleixner, Kate Stewart, Allison Randal,
	linux-media

On Tue, Mar 10, 2020 at 06:41:13PM -0700, Guru Das Srinagesh wrote:
> Since the PWM framework is switching struct pwm_state.period's datatype
> to u64, prepare for this transition by using DIV_ROUND_CLOSEST_ULL to
> handle a 64-bit dividend.
> 
> Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
> Cc: Richard Fontana <rfontana@redhat.com>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Kate Stewart <kstewart@linuxfoundation.org>
> Cc: Allison Randal <allison@lohutok.net>
> Cc: linux-media@vger.kernel.org

Acked-by: Sean Young <sean@mess.org>

> 
> Signed-off-by: Guru Das Srinagesh <gurus@codeaurora.org>
> ---
>  drivers/media/rc/ir-rx51.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/media/rc/ir-rx51.c b/drivers/media/rc/ir-rx51.c
> index 8574eda..9a5dfd7 100644
> --- a/drivers/media/rc/ir-rx51.c
> +++ b/drivers/media/rc/ir-rx51.c
> @@ -241,7 +241,8 @@ static int ir_rx51_probe(struct platform_device *dev)
>  	}
>  
>  	/* Use default, in case userspace does not set the carrier */
> -	ir_rx51.freq = DIV_ROUND_CLOSEST(pwm_get_period(pwm), NSEC_PER_SEC);
> +	ir_rx51.freq = DIV_ROUND_CLOSEST_ULL(pwm_get_period(pwm),
> +			NSEC_PER_SEC);
>  	pwm_put(pwm);
>  
>  	hrtimer_init(&ir_rx51.timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
> -- 
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project

^ permalink raw reply	[flat|nested] 22+ messages in thread

* Re: [PATCH v8 10/12] pwm: sun4i: Use 64-bit division function
  2020-03-11  1:41 ` [PATCH v8 10/12] pwm: sun4i: Use 64-bit division function Guru Das Srinagesh
@ 2020-03-11  3:35   ` Chen-Yu Tsai
  0 siblings, 0 replies; 22+ messages in thread
From: Chen-Yu Tsai @ 2020-03-11  3:35 UTC (permalink / raw)
  To: Guru Das Srinagesh
  Cc: linux-pwm, Thierry Reding, Uwe Kleine-König,
	Subbaraman Narayanamurthy, linux-kernel, Maxime Ripard,
	Philipp Zabel

On Wed, Mar 11, 2020 at 9:41 AM Guru Das Srinagesh <gurus@codeaurora.org> wrote:
>
> Since the PWM framework is switching struct pwm_state.period's datatype
> to u64, prepare for this transition by using div_u64 to handle a 64-bit
> dividend instead of a straight division operation.
>
> Cc: Maxime Ripard <mripard@kernel.org>
> Cc: Chen-Yu Tsai <wens@csie.org>
> Cc: Philipp Zabel <p.zabel@pengutronix.de>
>
> Signed-off-by: Guru Das Srinagesh <gurus@codeaurora.org>

Acked-by: Chen-Yu Tsai <wens@csie.org>

^ permalink raw reply	[flat|nested] 22+ messages in thread

* Re: [PATCH v8 11/12] backlight: pwm_bl: Use 64-bit division function
  2020-03-11  1:41 ` [PATCH v8 11/12] backlight: pwm_bl: " Guru Das Srinagesh
@ 2020-03-11 10:05   ` Daniel Thompson
  0 siblings, 0 replies; 22+ messages in thread
From: Daniel Thompson @ 2020-03-11 10:05 UTC (permalink / raw)
  To: Guru Das Srinagesh
  Cc: linux-pwm, Thierry Reding, Uwe Kleine-König,
	Subbaraman Narayanamurthy, linux-kernel, Lee Jones, Jingoo Han,
	Bartlomiej Zolnierkiewicz, dri-devel, linux-fbdev

On Tue, Mar 10, 2020 at 06:41:20PM -0700, Guru Das Srinagesh wrote:
> Since the PWM framework is switching struct pwm_state.period's datatype
> to u64, prepare for this transition by using div_u64 to handle a 64-bit
> dividend instead of a straight division operation.
> 
> Cc: Lee Jones <lee.jones@linaro.org>
> Cc: Daniel Thompson <daniel.thompson@linaro.org>
> Cc: Jingoo Han <jingoohan1@gmail.com>
> Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
> Cc: linux-pwm@vger.kernel.org
> Cc: dri-devel@lists.freedesktop.org
> Cc: linux-fbdev@vger.kernel.org
> 
> Signed-off-by: Guru Das Srinagesh <gurus@codeaurora.org>

Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>

> ---
>  drivers/video/backlight/pwm_bl.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
> index efb4efc..3e5dbcf 100644
> --- a/drivers/video/backlight/pwm_bl.c
> +++ b/drivers/video/backlight/pwm_bl.c
> @@ -625,7 +625,8 @@ static int pwm_backlight_probe(struct platform_device *pdev)
>  		pb->scale = data->max_brightness;
>  	}
>  
> -	pb->lth_brightness = data->lth_brightness * (state.period / pb->scale);
> +	pb->lth_brightness = data->lth_brightness * (div_u64(state.period,
> +				pb->scale));
>  
>  	props.type = BACKLIGHT_RAW;
>  	props.max_brightness = data->max_brightness;
> -- 
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project
> 

^ permalink raw reply	[flat|nested] 22+ messages in thread

* Re: [PATCH v8 03/12] hwmon: pwm-fan: Use 64-bit division macro
  2020-03-11  1:41 ` [PATCH v8 03/12] hwmon: pwm-fan: " Guru Das Srinagesh
@ 2020-03-11 15:08   ` Guenter Roeck
  0 siblings, 0 replies; 22+ messages in thread
From: Guenter Roeck @ 2020-03-11 15:08 UTC (permalink / raw)
  To: Guru Das Srinagesh
  Cc: linux-pwm, Thierry Reding, Uwe Kleine-König,
	Subbaraman Narayanamurthy, linux-kernel, Kamil Debski,
	Bartlomiej Zolnierkiewicz, Jean Delvare, Liam Girdwood,
	Mark Brown, linux-hwmon

On Tue, Mar 10, 2020 at 06:41:12PM -0700, Guru Das Srinagesh wrote:
> Since the PWM framework is switching struct pwm_args.period's datatype
> to u64, prepare for this transition by using DIV_ROUND_UP_ULL to handle
> a 64-bit dividend.
> 
> Cc: Kamil Debski <kamil@wypas.org>
> Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
> Cc: Jean Delvare <jdelvare@suse.com>
> Cc: Guenter Roeck <linux@roeck-us.net>
> Cc: Liam Girdwood <lgirdwood@gmail.com>
> Cc: Mark Brown <broonie@kernel.org>
> Cc: linux-hwmon@vger.kernel.org
> 
> Signed-off-by: Guru Das Srinagesh <gurus@codeaurora.org>

Not sure if I entirely buy the use case, but then the performance
impact is minimal, at least for this driver, so

Acked-by: Guenter Roeck <linux@roeck-us.net>

Guenter

> ---
>  drivers/hwmon/pwm-fan.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c
> index 42ffd2e..283423a 100644
> --- a/drivers/hwmon/pwm-fan.c
> +++ b/drivers/hwmon/pwm-fan.c
> @@ -437,7 +437,7 @@ static int pwm_fan_resume(struct device *dev)
>  		return 0;
>  
>  	pwm_get_args(ctx->pwm, &pargs);
> -	duty = DIV_ROUND_UP(ctx->pwm_value * (pargs.period - 1), MAX_PWM);
> +	duty = DIV_ROUND_UP_ULL(ctx->pwm_value * (pargs.period - 1), MAX_PWM);
>  	ret = pwm_config(ctx->pwm, duty, pargs.period);
>  	if (ret)
>  		return ret;
> -- 
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project
> 

^ permalink raw reply	[flat|nested] 22+ messages in thread

* RE: [PATCH v8 01/12] clk: pwm: Use 64-bit division function
  2020-03-11  1:41 ` [PATCH v8 01/12] clk: pwm: Use 64-bit division function Guru Das Srinagesh
@ 2020-03-11 16:58   ` David Laight
  2020-03-12  2:09     ` Guru Das Srinagesh
  0 siblings, 1 reply; 22+ messages in thread
From: David Laight @ 2020-03-11 16:58 UTC (permalink / raw)
  To: 'Guru Das Srinagesh', linux-pwm
  Cc: Thierry Reding, Uwe Kleine-König, Subbaraman Narayanamurthy,
	linux-kernel, Michael Turquette, Stephen Boyd, linux-clk

From: Guru Das Srinagesh
> Sent: 11 March 2020 01:41
> 
> Since the PWM framework is switching struct pwm_args.period's datatype
> to u64, prepare for this transition by using div64_u64 to handle a
> 64-bit divisor.
> 
> Cc: Michael Turquette <mturquette@baylibre.com>
> Cc: Stephen Boyd <sboyd@kernel.org>
> Cc: linux-clk@vger.kernel.org
> 
> Signed-off-by: Guru Das Srinagesh <gurus@codeaurora.org>
> ---
>  drivers/clk/clk-pwm.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/clk/clk-pwm.c b/drivers/clk/clk-pwm.c
> index 87fe0b0e..7b1f7a0 100644
> --- a/drivers/clk/clk-pwm.c
> +++ b/drivers/clk/clk-pwm.c
> @@ -89,7 +89,7 @@ static int clk_pwm_probe(struct platform_device *pdev)
>  	}
> 
>  	if (of_property_read_u32(node, "clock-frequency", &clk_pwm->fixed_rate))
> -		clk_pwm->fixed_rate = NSEC_PER_SEC / pargs.period;
> +		clk_pwm->fixed_rate = div64_u64(NSEC_PER_SEC, pargs.period);

That cannot be needed, a 32 bit division is fine.
More interesting would be whether pargs.period is sane (eg not zero).
I'd assign pargs.period to an 'unsigned int' variable
prior to the division (I hate casts - been bitten by them in the past.).

> 
>  	if (pargs.period != NSEC_PER_SEC / clk_pwm->fixed_rate &&
>  	    pargs.period != DIV_ROUND_UP(NSEC_PER_SEC, clk_pwm->fixed_rate)) {
> --
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project

	David

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)


^ permalink raw reply	[flat|nested] 22+ messages in thread

* Re: [PATCH v8 01/12] clk: pwm: Use 64-bit division function
  2020-03-11 16:58   ` David Laight
@ 2020-03-12  2:09     ` Guru Das Srinagesh
  2020-03-12  9:14       ` David Laight
  0 siblings, 1 reply; 22+ messages in thread
From: Guru Das Srinagesh @ 2020-03-12  2:09 UTC (permalink / raw)
  To: David Laight
  Cc: linux-pwm, Thierry Reding, Uwe Kleine-König,
	Subbaraman Narayanamurthy, linux-kernel, Michael Turquette,
	Stephen Boyd, linux-clk

On Wed, Mar 11, 2020 at 04:58:24PM +0000, David Laight wrote:
> From: Guru Das Srinagesh
> > Sent: 11 March 2020 01:41
> > 
> > Since the PWM framework is switching struct pwm_args.period's datatype
> > to u64, prepare for this transition by using div64_u64 to handle a
> > 64-bit divisor.
> > 
> > Cc: Michael Turquette <mturquette@baylibre.com>
> > Cc: Stephen Boyd <sboyd@kernel.org>
> > Cc: linux-clk@vger.kernel.org
> > 
> > Signed-off-by: Guru Das Srinagesh <gurus@codeaurora.org>
> > ---
> >  drivers/clk/clk-pwm.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/clk/clk-pwm.c b/drivers/clk/clk-pwm.c
> > index 87fe0b0e..7b1f7a0 100644
> > --- a/drivers/clk/clk-pwm.c
> > +++ b/drivers/clk/clk-pwm.c
> > @@ -89,7 +89,7 @@ static int clk_pwm_probe(struct platform_device *pdev)
> >  	}
> > 
> >  	if (of_property_read_u32(node, "clock-frequency", &clk_pwm->fixed_rate))
> > -		clk_pwm->fixed_rate = NSEC_PER_SEC / pargs.period;
> > +		clk_pwm->fixed_rate = div64_u64(NSEC_PER_SEC, pargs.period);
> 
> That cannot be needed, a 32 bit division is fine.

Could you please explain why? I think the use of this function is
warranted in order to handle the division properly with a 64-bit
divisor.

> More interesting would be whether pargs.period is sane (eg not zero).

There is a non-zero check for pargs.period just prior to this line, so
the code is handling this case already.

> I'd assign pargs.period to an 'unsigned int' variable
> prior to the division (I hate casts - been bitten by them in the past.).

Wouldn't this truncate the 64-bit value? The intention behind this patch
is to allow the processing of 64-bit values in full.

Thank you.

Guru Das.

^ permalink raw reply	[flat|nested] 22+ messages in thread

* RE: [PATCH v8 01/12] clk: pwm: Use 64-bit division function
  2020-03-12  2:09     ` Guru Das Srinagesh
@ 2020-03-12  9:14       ` David Laight
  2020-03-12 19:09         ` Guru Das Srinagesh
  2020-04-09  2:40         ` Guru Das Srinagesh
  0 siblings, 2 replies; 22+ messages in thread
From: David Laight @ 2020-03-12  9:14 UTC (permalink / raw)
  To: 'Guru Das Srinagesh'
  Cc: linux-pwm, Thierry Reding, Uwe Kleine-König,
	Subbaraman Narayanamurthy, linux-kernel, Michael Turquette,
	Stephen Boyd, linux-clk

From: Guru Das Srinagesh
> Sent: 12 March 2020 02:10
> On Wed, Mar 11, 2020 at 04:58:24PM +0000, David Laight wrote:
> > From: Guru Das Srinagesh
> > > Sent: 11 March 2020 01:41
> > >
> > > Since the PWM framework is switching struct pwm_args.period's datatype
> > > to u64, prepare for this transition by using div64_u64 to handle a
> > > 64-bit divisor.
> > >
...
> > > --- a/drivers/clk/clk-pwm.c
> > > +++ b/drivers/clk/clk-pwm.c
> > > @@ -89,7 +89,7 @@ static int clk_pwm_probe(struct platform_device *pdev)
> > >  	}
> > >
> > >  	if (of_property_read_u32(node, "clock-frequency", &clk_pwm->fixed_rate))
> > > -		clk_pwm->fixed_rate = NSEC_PER_SEC / pargs.period;
> > > +		clk_pwm->fixed_rate = div64_u64(NSEC_PER_SEC, pargs.period);
> >
> > That cannot be needed, a 32 bit division is fine.
> 
> Could you please explain why? I think the use of this function is
> warranted in order to handle the division properly with a 64-bit
> divisor.
...
> > I'd assign pargs.period to an 'unsigned int' variable
> > prior to the division (I hate casts - been bitten by them in the past.).
> 
> Wouldn't this truncate the 64-bit value? The intention behind this patch
> is to allow the processing of 64-bit values in full.

You are dividing a 32bit constant by a value.
If pargs.period is greater than 2^32 the result is zero.
I think you divide by 'fixed_rate' a bit later on - better not be zero.

	David

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)


^ permalink raw reply	[flat|nested] 22+ messages in thread

* Re: [PATCH v8 01/12] clk: pwm: Use 64-bit division function
  2020-03-12  9:14       ` David Laight
@ 2020-03-12 19:09         ` Guru Das Srinagesh
  2020-03-19 20:53           ` Guru Das Srinagesh
  2020-04-09  2:40         ` Guru Das Srinagesh
  1 sibling, 1 reply; 22+ messages in thread
From: Guru Das Srinagesh @ 2020-03-12 19:09 UTC (permalink / raw)
  To: David Laight
  Cc: linux-pwm, Thierry Reding, Uwe Kleine-König,
	Subbaraman Narayanamurthy, linux-kernel, Michael Turquette,
	Stephen Boyd, linux-clk

On Thu, Mar 12, 2020 at 09:14:09AM +0000, David Laight wrote:
> From: Guru Das Srinagesh
> > Sent: 12 March 2020 02:10
> > On Wed, Mar 11, 2020 at 04:58:24PM +0000, David Laight wrote:
> > > From: Guru Das Srinagesh
> > > > Sent: 11 March 2020 01:41
> > > >
> > > > Since the PWM framework is switching struct pwm_args.period's datatype
> > > > to u64, prepare for this transition by using div64_u64 to handle a
> > > > 64-bit divisor.
> > > >
> ...
> > > > --- a/drivers/clk/clk-pwm.c
> > > > +++ b/drivers/clk/clk-pwm.c
> > > > @@ -89,7 +89,7 @@ static int clk_pwm_probe(struct platform_device *pdev)
> > > >  	}
> > > >
> > > >  	if (of_property_read_u32(node, "clock-frequency", &clk_pwm->fixed_rate))
> > > > -		clk_pwm->fixed_rate = NSEC_PER_SEC / pargs.period;
> > > > +		clk_pwm->fixed_rate = div64_u64(NSEC_PER_SEC, pargs.period);
> > >
> > > That cannot be needed, a 32 bit division is fine.
> > 
> > Could you please explain why? I think the use of this function is
> > warranted in order to handle the division properly with a 64-bit
> > divisor.
> ...
> > > I'd assign pargs.period to an 'unsigned int' variable
> > > prior to the division (I hate casts - been bitten by them in the past.).
> > 
> > Wouldn't this truncate the 64-bit value? The intention behind this patch
> > is to allow the processing of 64-bit values in full.
> 
> You are dividing a 32bit constant by a value.
> If pargs.period is greater than 2^32 the result is zero.

Thanks for the explanation. 

> I think you divide by 'fixed_rate' a bit later on - better not be zero.

Good point, but this issue exists with or without this patch, and fixing
it is beyond this patch's scope.

Just to check if this patch can be dropped, I tested out compilation
with this patch reverted and there were no errors, so I'm leaning
towards dropping this patch unless you have any further comments on how
to proceed.

Thank you.

Guru Das.

^ permalink raw reply	[flat|nested] 22+ messages in thread

* Re: [PATCH v8 01/12] clk: pwm: Use 64-bit division function
  2020-03-12 19:09         ` Guru Das Srinagesh
@ 2020-03-19 20:53           ` Guru Das Srinagesh
  0 siblings, 0 replies; 22+ messages in thread
From: Guru Das Srinagesh @ 2020-03-19 20:53 UTC (permalink / raw)
  To: David Laight
  Cc: linux-pwm, Thierry Reding, Uwe Kleine-König,
	Subbaraman Narayanamurthy, linux-kernel, Michael Turquette,
	Stephen Boyd, linux-clk

On Thu, Mar 12, 2020 at 12:09:12PM -0700, Guru Das Srinagesh wrote:
> On Thu, Mar 12, 2020 at 09:14:09AM +0000, David Laight wrote:
> > From: Guru Das Srinagesh
> > > Sent: 12 March 2020 02:10
> > > On Wed, Mar 11, 2020 at 04:58:24PM +0000, David Laight wrote:
> > > > From: Guru Das Srinagesh
> > > > > Sent: 11 March 2020 01:41
> > > > >
> > > > > Since the PWM framework is switching struct pwm_args.period's datatype
> > > > > to u64, prepare for this transition by using div64_u64 to handle a
> > > > > 64-bit divisor.
> > > > >
> > ...
> > > > > --- a/drivers/clk/clk-pwm.c
> > > > > +++ b/drivers/clk/clk-pwm.c
> > > > > @@ -89,7 +89,7 @@ static int clk_pwm_probe(struct platform_device *pdev)
> > > > >  	}
> > > > >
> > > > >  	if (of_property_read_u32(node, "clock-frequency", &clk_pwm->fixed_rate))
> > > > > -		clk_pwm->fixed_rate = NSEC_PER_SEC / pargs.period;
> > > > > +		clk_pwm->fixed_rate = div64_u64(NSEC_PER_SEC, pargs.period);
> > > >
> > > > That cannot be needed, a 32 bit division is fine.
> > > 
> > > Could you please explain why? I think the use of this function is
> > > warranted in order to handle the division properly with a 64-bit
> > > divisor.
> > ...
> > > > I'd assign pargs.period to an 'unsigned int' variable
> > > > prior to the division (I hate casts - been bitten by them in the past.).
> > > 
> > > Wouldn't this truncate the 64-bit value? The intention behind this patch
> > > is to allow the processing of 64-bit values in full.
> > 
> > You are dividing a 32bit constant by a value.
> > If pargs.period is greater than 2^32 the result is zero.
> 
> Thanks for the explanation. 
> 
> > I think you divide by 'fixed_rate' a bit later on - better not be zero.
> 
> Good point, but this issue exists with or without this patch, and fixing
> it is beyond this patch's scope.
> 
> Just to check if this patch can be dropped, I tested out compilation
> with this patch reverted and there were no errors, so I'm leaning
> towards dropping this patch unless you have any further comments on how
> to proceed.

Turns out I couldn't drop this patch after all - kbuild test robot
complained [1]. Accordingly, I've brought this patch back in my v10
patchset with the modifications you suggested. Could you kindly review it?

[1] https://www.spinics.net/lists/linux-pwm/msg11906.html

Thank you.

Guru Das.

^ permalink raw reply	[flat|nested] 22+ messages in thread

* Re: [PATCH v8 01/12] clk: pwm: Use 64-bit division function
  2020-03-12  9:14       ` David Laight
  2020-03-12 19:09         ` Guru Das Srinagesh
@ 2020-04-09  2:40         ` Guru Das Srinagesh
  1 sibling, 0 replies; 22+ messages in thread
From: Guru Das Srinagesh @ 2020-04-09  2:40 UTC (permalink / raw)
  To: David Laight
  Cc: linux-pwm, Thierry Reding, Uwe Kleine-König,
	Subbaraman Narayanamurthy, linux-kernel, Michael Turquette,
	Stephen Boyd, linux-clk

On Thu, Mar 12, 2020 at 09:14:09AM +0000, David Laight wrote:
> From: Guru Das Srinagesh
> > Sent: 12 March 2020 02:10
> > On Wed, Mar 11, 2020 at 04:58:24PM +0000, David Laight wrote:
> > > From: Guru Das Srinagesh
> > > > Sent: 11 March 2020 01:41
> > > >
> > > > Since the PWM framework is switching struct pwm_args.period's datatype
> > > > to u64, prepare for this transition by using div64_u64 to handle a
> > > > 64-bit divisor.
> > > >
> ...
> > > > --- a/drivers/clk/clk-pwm.c
> > > > +++ b/drivers/clk/clk-pwm.c
> > > > @@ -89,7 +89,7 @@ static int clk_pwm_probe(struct platform_device *pdev)
> > > >  	}
> > > >
> > > >  	if (of_property_read_u32(node, "clock-frequency", &clk_pwm->fixed_rate))
> > > > -		clk_pwm->fixed_rate = NSEC_PER_SEC / pargs.period;
> > > > +		clk_pwm->fixed_rate = div64_u64(NSEC_PER_SEC, pargs.period);
> > >
> > > That cannot be needed, a 32 bit division is fine.
> > 
> > Could you please explain why? I think the use of this function is
> > warranted in order to handle the division properly with a 64-bit
> > divisor.
> ...
> > > I'd assign pargs.period to an 'unsigned int' variable
> > > prior to the division (I hate casts - been bitten by them in the past.).
> > 
> > Wouldn't this truncate the 64-bit value? The intention behind this patch
> > is to allow the processing of 64-bit values in full.
> 
> You are dividing a 32bit constant by a value.
> If pargs.period is greater than 2^32 the result is zero.

Correction: if pargs.period is greater than NSEC_PER_SEC, not 2^32.

> I think you divide by 'fixed_rate' a bit later on - better not be zero.

I am adding an explicit check in v12 to ensure fixed_rate is not zero. If
during the calculation it is found to be zero, probing will fail.

I think with this modification, this v8 version of this change makes
sense to use.

Thank you.

Guru Das.

^ permalink raw reply	[flat|nested] 22+ messages in thread

end of thread, other threads:[~2020-04-09  2:40 UTC | newest]

Thread overview: 22+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
     [not found] <cover.1583889178.git.gurus@codeaurora.org>
2020-03-11  1:41 ` [PATCH v8 01/12] clk: pwm: Use 64-bit division function Guru Das Srinagesh
2020-03-11 16:58   ` David Laight
2020-03-12  2:09     ` Guru Das Srinagesh
2020-03-12  9:14       ` David Laight
2020-03-12 19:09         ` Guru Das Srinagesh
2020-03-19 20:53           ` Guru Das Srinagesh
2020-04-09  2:40         ` Guru Das Srinagesh
2020-03-11  1:41 ` [PATCH v8 02/12] drm/i915: Use 64-bit division macro Guru Das Srinagesh
2020-03-11  1:41 ` [PATCH v8 03/12] hwmon: pwm-fan: " Guru Das Srinagesh
2020-03-11 15:08   ` Guenter Roeck
2020-03-11  1:41 ` [PATCH v8 04/12] ir-rx51: " Guru Das Srinagesh
2020-03-11  2:11   ` Sean Young
2020-03-11  1:41 ` [PATCH v8 05/12] pwm: clps711x: " Guru Das Srinagesh
2020-03-11  1:41 ` [PATCH v8 06/12] pwm: pwm-imx-tpm: " Guru Das Srinagesh
2020-03-11  1:41 ` [PATCH v8 07/12] pwm: imx27: Use 64-bit division macro and function Guru Das Srinagesh
2020-03-11  1:41 ` [PATCH v8 08/12] pwm: sifive: Use 64-bit division macro Guru Das Srinagesh
2020-03-11  1:41 ` [PATCH v8 09/12] pwm: stm32-lp: Use %llu format specifier for period Guru Das Srinagesh
2020-03-11  1:41 ` [PATCH v8 10/12] pwm: sun4i: Use 64-bit division function Guru Das Srinagesh
2020-03-11  3:35   ` Chen-Yu Tsai
2020-03-11  1:41 ` [PATCH v8 11/12] backlight: pwm_bl: " Guru Das Srinagesh
2020-03-11 10:05   ` Daniel Thompson
2020-03-11  1:41 ` [PATCH v8 12/12] pwm: core: Convert period and duty cycle to u64 Guru Das Srinagesh

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