linux-kernel - [PATCH v2 3/8] drm/msm/dsi: Flip greater-than check for slice_count and slice_per

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20221221231943.1961117-4-marijn.suijten@somainline.org>
Date:   Thu, 22 Dec 2022 00:19:38 +0100
From:   Marijn Suijten <marijn.suijten@...ainline.org>
To:     phone-devel@...r.kernel.org, Rob Clark <robdclark@...il.com>,
        Abhinav Kumar <quic_abhinavk@...cinc.com>,
        Dmitry Baryshkov <dmitry.baryshkov@...aro.org>,
        Vinod Koul <vkoul@...nel.org>
Cc:     ~postmarketos/upstreaming@...ts.sr.ht,
        AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@...ainline.org>,
        Konrad Dybcio <konrad.dybcio@...ainline.org>,
        Martin Botka <martin.botka@...ainline.org>,
        Jami Kettunen <jami.kettunen@...ainline.org>,
        Marijn Suijten <marijn.suijten@...ainline.org>,
        Sean Paul <sean@...rly.run>, David Airlie <airlied@...il.com>,
        Daniel Vetter <daniel@...ll.ch>,
        Stephen Boyd <swboyd@...omium.org>,
        Bjorn Andersson <andersson@...nel.org>,
        Jessica Zhang <quic_jesszhan@...cinc.com>,
        Ville Syrjälä 
        <ville.syrjala@...ux.intel.com>,
        Kuogee Hsieh <quic_khsieh@...cinc.com>,
        Jani Nikula <jani.nikula@...el.com>,
        sunliming <sunliming@...inos.cn>,
        Sam Ravnborg <sam@...nborg.org>,
        Haowen Bai <baihaowen@...zu.com>,
        Konrad Dybcio <konrad.dybcio@...aro.org>,
        Loic Poulain <loic.poulain@...aro.org>,
        Vinod Polimera <quic_vpolimer@...cinc.com>,
        Douglas Anderson <dianders@...omium.org>,
        Vladimir Lypak <vladimir.lypak@...il.com>,
        linux-arm-msm@...r.kernel.org, dri-devel@...ts.freedesktop.org,
        freedreno@...ts.freedesktop.org, linux-kernel@...r.kernel.org
Subject: [PATCH v2 3/8] drm/msm/dsi: Flip greater-than check for slice_count and slice_per_intf

According to downstream /and the comment copied from it/ this comparison
should be the other way around.  In other words, when the panel driver
requests to use more slices per packet than what could be sent over this
interface, it is bumped down to only use a single slice per packet (and
strangely not the number of slices that could fit on the interface).

Fixes: 08802f515c3c ("drm/msm/dsi: Add support for DSC configuration")
Signed-off-by: Marijn Suijten <marijn.suijten@...ainline.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
Reviewed-by: Abhinav Kumar <quic_abhinavk@...cinc.com>
---
 drivers/gpu/drm/msm/dsi/dsi_host.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c
index 0686c35a6fd4..3409a4275d4a 100644
--- a/drivers/gpu/drm/msm/dsi/dsi_host.c
+++ b/drivers/gpu/drm/msm/dsi/dsi_host.c
@@ -855,11 +855,12 @@ static void dsi_update_dsc_timing(struct msm_dsi_host *msm_host, bool is_cmd_mod
 	 */
 	slice_per_intf = DIV_ROUND_UP(hdisplay, dsc->slice_width);
 
-	/* If slice_per_pkt is greater than slice_per_intf
+	/*
+	 * If slice_count is greater than slice_per_intf
 	 * then default to 1. This can happen during partial
 	 * update.
 	 */
-	if (slice_per_intf > dsc->slice_count)
+	if (dsc->slice_count > slice_per_intf)
 		dsc->slice_count = 1;
 
 	total_bytes_per_intf = dsc->slice_chunk_size * slice_per_intf;
-- 
2.39.0