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drm/msms/dp: fixed link clock divider bits be over written in BPC unknown case

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[ Upstream commit 77e8aad5519e04f6c1e132aaec1c5f8faf41844f ]

Since the value of DP_TEST_BIT_DEPTH_8 is already left shifted, in the
BPC unknown case, the additional shift causes spill over to the other
bits of the [DP_CONFIGURATION_CTRL] register.
Fix this by changing the return value of dp_link_get_test_bits_depth()
in the BPC unknown case to (DP_TEST_BIT_DEPTH_8 >> DP_TEST_BIT_DEPTH_SHIFT).

Fixes: c943b4948b58 ("drm/msm/dp: add displayPort driver support")
Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/573989/
Link: https://lore.kernel.org/r/1704917931-30133-1-git-send-email-quic_khsieh@quicinc.com
[quic_abhinavk@quicinc.com: fix minor checkpatch warning to align with opening braces]
Signed-off-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Kuogee Hsieh 2024-01-10 12:18:51 -08:00 committed by Greg Kroah-Hartman
parent 05955a703b
commit 1506145c2c
2 changed files with 7 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
drivers/gpu/drm/msm/dp/dp_ctrl.c
View File

@ -135,11 +135,6 @@ static void dp_ctrl_config_ctrl(struct dp_ctrl_private *ctrl)
tbd = dp_link_get_test_bits_depth(ctrl->link,
ctrl->panel->dp_mode.bpp);
if (tbd == DP_TEST_BIT_DEPTH_UNKNOWN) {
pr_debug("BIT_DEPTH not set. Configure default\n");
tbd = DP_TEST_BIT_DEPTH_8;
}
config |= tbd << DP_CONFIGURATION_CTRL_BPC_SHIFT;
/* Num of Lanes */

10
drivers/gpu/drm/msm/dp/dp_link.c
View File

@ -1211,6 +1211,9 @@ void dp_link_reset_phy_params_vx_px(struct dp_link *dp_link)
u32 dp_link_get_test_bits_depth(struct dp_link *dp_link, u32 bpp)
{
u32 tbd;
struct dp_link_private *link;
link = container_of(dp_link, struct dp_link_private, dp_link);
/*
* Few simplistic rules and assumptions made here:
@ -1228,12 +1231,13 @@ u32 dp_link_get_test_bits_depth(struct dp_link *dp_link, u32 bpp)
tbd = DP_TEST_BIT_DEPTH_10;
break;
default:
tbd = DP_TEST_BIT_DEPTH_UNKNOWN;
drm_dbg_dp(link->drm_dev, "bpp=%d not supported, use bpc=8\n",
bpp);
tbd = DP_TEST_BIT_DEPTH_8;
break;
}
if (tbd != DP_TEST_BIT_DEPTH_UNKNOWN)
tbd = (tbd >> DP_TEST_BIT_DEPTH_SHIFT);
tbd = (tbd >> DP_TEST_BIT_DEPTH_SHIFT);
return tbd;
}