LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Icenowy Zheng <icenowy@aosc.io>
To: Thierry Reding <thierry.reding@gmail.com>,
	Sam Ravnborg <sam@ravnborg.org>, Rob Herring <robh+dt@kernel.org>,
	Maxime Ripard <mripard@kernel.org>, Chen-Yu Tsai <wens@csie.org>,
	Ondrej Jirman <megous@megous.com>
Cc: dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-sunxi@googlegroups.com, Icenowy Zheng <icenowy@aosc.io>
Subject: [PATCH 4/5] drm/sun4i: sun6i_mipi_dsi: fix horizontal timing calculation
Date: Thu, 12 Mar 2020 00:33:28 +0800	[thread overview]
Message-ID: <20200311163329.221840-5-icenowy@aosc.io> (raw)
In-Reply-To: <20200311163329.221840-1-icenowy@aosc.io>

The max() function call in horizontal timing calculation shouldn't pad a
length already subtracted with overhead to overhead, instead it should
only prevent the set timing to underflow.

Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
---
 drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
index 059939789730..5f2313c40328 100644
--- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
+++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
@@ -555,7 +555,7 @@ static void sun6i_dsi_setup_timings(struct sun6i_dsi *dsi,
 		 */
 #define HSA_PACKET_OVERHEAD	10
 		hsa = max((unsigned int)HSA_PACKET_OVERHEAD,
-			  (mode->hsync_end - mode->hsync_start) * Bpp - HSA_PACKET_OVERHEAD);
+			  (mode->hsync_end - mode->hsync_start) * Bpp) - HSA_PACKET_OVERHEAD;
 
 		/*
 		 * The backporch is set using a blanking packet (4
@@ -564,7 +564,7 @@ static void sun6i_dsi_setup_timings(struct sun6i_dsi *dsi,
 		 */
 #define HBP_PACKET_OVERHEAD	6
 		hbp = max((unsigned int)HBP_PACKET_OVERHEAD,
-			  (mode->htotal - mode->hsync_end) * Bpp - HBP_PACKET_OVERHEAD);
+			  (mode->htotal - mode->hsync_end) * Bpp) - HBP_PACKET_OVERHEAD;
 
 		/*
 		 * The frontporch is set using a sync event (4 bytes)
@@ -574,7 +574,7 @@ static void sun6i_dsi_setup_timings(struct sun6i_dsi *dsi,
 		 */
 #define HFP_PACKET_OVERHEAD	16
 		hfp = max((unsigned int)HFP_PACKET_OVERHEAD,
-			  (mode->hsync_start - mode->hdisplay) * Bpp - HFP_PACKET_OVERHEAD);
+			  (mode->hsync_start - mode->hdisplay) * Bpp) - HFP_PACKET_OVERHEAD;
 
 		/*
 		 * The blanking is set using a sync event (4 bytes)
@@ -583,8 +583,8 @@ static void sun6i_dsi_setup_timings(struct sun6i_dsi *dsi,
 		 */
 #define HBLK_PACKET_OVERHEAD	10
 		hblk = max((unsigned int)HBLK_PACKET_OVERHEAD,
-			   (mode->htotal - (mode->hsync_end - mode->hsync_start)) * Bpp -
-			   HBLK_PACKET_OVERHEAD);
+			   (mode->htotal - (mode->hsync_end - mode->hsync_start)) * Bpp) -
+			   HBLK_PACKET_OVERHEAD;
 
 		/*
 		 * And I'm not entirely sure what vblk is about. The driver in
-- 
2.24.1


  parent reply	other threads:[~2020-03-11 16:34 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-11 16:33 [PATCH 0/5] Add support for PinePhone LCD panel Icenowy Zheng
2020-03-11 16:33 ` [PATCH 1/5] dt-bindings: vendor-prefixes: Add Xingbangda Icenowy Zheng
2020-03-11 16:33 ` [PATCH 2/5] dt-bindings: panel: add binding for Xingbangda XBD599 panel Icenowy Zheng
2020-03-12 15:45   ` Rob Herring
2020-03-14  7:41   ` Sam Ravnborg
2020-03-11 16:33 ` [PATCH 3/5] drm: panel: add " Icenowy Zheng
2020-03-14  8:00   ` Sam Ravnborg
2020-03-14  8:02     ` Icenowy Zheng
2020-03-14  8:16       ` Sam Ravnborg
2020-03-11 16:33 ` Icenowy Zheng [this message]
2020-03-11 16:33 ` [PATCH 5/5] arm64: allwinner: dts: a64: add LCD-related device nodes for PinePhone Icenowy Zheng

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200311163329.221840-5-icenowy@aosc.io \
    --to=icenowy@aosc.io \
    --cc=devicetree@vger.kernel.org \
    --cc=dri-devel@lists.freedesktop.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-sunxi@googlegroups.com \
    --cc=megous@megous.com \
    --cc=mripard@kernel.org \
    --cc=robh+dt@kernel.org \
    --cc=sam@ravnborg.org \
    --cc=thierry.reding@gmail.com \
    --cc=wens@csie.org \
    --subject='Re: [PATCH 4/5] drm/sun4i: sun6i_mipi_dsi: fix horizontal timing calculation' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).