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From: Baolin Wang <baolin.wang@linaro.org>
To: wsa@the-dreams.de
Cc: broonie@kernel.org, baolin.wang@linaro.org,
	linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH 2/2] i2c: sprd: Fix the i2c count issue
Date: Mon,  9 Apr 2018 14:40:55 +0800	[thread overview]
Message-ID: <e42cc3e001d612e811166b8d21f44802ff20069e.1523255712.git.baolin.wang@linaro.org> (raw)
In-Reply-To: <99031524fa147e72451d26f54b24f36093c0d3fa.1523255712.git.baolin.wang@linaro.org>
In-Reply-To: <99031524fa147e72451d26f54b24f36093c0d3fa.1523255712.git.baolin.wang@linaro.org>

We found the I2C controller count register is unreliable sometimes,
that will cause I2C to lose data. Thus we can read the data count
from 'i2c_dev->count' instead of the I2C controller count register.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
---
 drivers/i2c/busses/i2c-sprd.c |    6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/i2c/busses/i2c-sprd.c b/drivers/i2c/busses/i2c-sprd.c
index 2fdad63..4053259 100644
--- a/drivers/i2c/busses/i2c-sprd.c
+++ b/drivers/i2c/busses/i2c-sprd.c
@@ -368,13 +368,12 @@ static irqreturn_t sprd_i2c_isr_thread(int irq, void *dev_id)
 	struct sprd_i2c *i2c_dev = dev_id;
 	struct i2c_msg *msg = i2c_dev->msg;
 	bool ack = !(readl(i2c_dev->base + I2C_STATUS) & I2C_RX_ACK);
-	u32 i2c_count = readl(i2c_dev->base + I2C_COUNT);
 	u32 i2c_tran;
 
 	if (msg->flags & I2C_M_RD)
 		i2c_tran = i2c_dev->count >= I2C_FIFO_FULL_THLD;
 	else
-		i2c_tran = i2c_count;
+		i2c_tran = i2c_dev->count;
 
 	/*
 	 * If we got one ACK from slave when writing data, and we did not
@@ -412,14 +411,13 @@ static irqreturn_t sprd_i2c_isr(int irq, void *dev_id)
 {
 	struct sprd_i2c *i2c_dev = dev_id;
 	struct i2c_msg *msg = i2c_dev->msg;
-	u32 i2c_count = readl(i2c_dev->base + I2C_COUNT);
 	bool ack = !(readl(i2c_dev->base + I2C_STATUS) & I2C_RX_ACK);
 	u32 i2c_tran;
 
 	if (msg->flags & I2C_M_RD)
 		i2c_tran = i2c_dev->count >= I2C_FIFO_FULL_THLD;
 	else
-		i2c_tran = i2c_count;
+		i2c_tran = i2c_dev->count;
 
 	/*
 	 * If we did not get one ACK from slave when writing data, then we
-- 
1.7.9.5

  reply	other threads:[~2018-04-09  6:41 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-09  6:40 [PATCH 1/2] i2c: sprd: Prevent i2c accesses after suspend is called Baolin Wang
2018-04-09  6:40 ` Baolin Wang [this message]
2018-04-27 12:14   ` [PATCH 2/2] i2c: sprd: Fix the i2c count issue Wolfram Sang
2018-04-09 20:56 ` [PATCH 1/2] i2c: sprd: Prevent i2c accesses after suspend is called Grygorii Strashko
2018-04-10  8:08   ` Baolin Wang
2018-04-27 12:14 ` Wolfram Sang
2018-05-02  3:27   ` Baolin Wang
2018-05-02  5:23     ` Wolfram Sang
2018-05-02  5:48       ` Baolin Wang
2018-05-03 16:26         ` Grygorii Strashko
2018-05-04 12:24           ` I2C PM overhaul needed? (Re: [PATCH 1/2] i2c: sprd: Prevent i2c accesses after suspend is called) Wolfram Sang
2018-05-05  1:54             ` Mark Brown
2018-05-05  8:32               ` Wolfram Sang
2018-05-09  8:18                 ` Mark Brown
2018-05-07 17:48             ` Grygorii Strashko
2018-05-08 16:32               ` Wolfram Sang
2018-05-08 18:31                 ` Peter Rosin
2018-05-11 15:14                 ` Grygorii Strashko

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