From 77e8aad5519e04f6c1e132aaec1c5f8faf41844f Mon Sep 17 00:00:00 2001
From: Kuogee Hsieh <quic_khsieh@quicinc.com>
Date: Wed, 10 Jan 2024 12:18:51 -0800
Subject: [PATCH] drm/msms/dp: fixed link clock divider bits be over written in BPC unknown case
Git-commit: 77e8aad5519e04f6c1e132aaec1c5f8faf41844f
Patch-mainline: v6.8-rc4
References: git-fixes
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>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/gpu/drm/msm/dp/dp_ctrl.c | 5 -----
drivers/gpu/drm/msm/dp/dp_link.c | 10 +++++++---
2 files changed, 7 insertions(+), 8 deletions(-)
diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c b/drivers/gpu/drm/msm/dp/dp_ctrl.c
index 77a8d9366ed7..fb588fde298a 100644
--- a/drivers/gpu/drm/msm/dp/dp_ctrl.c
+++ b/drivers/gpu/drm/msm/dp/dp_ctrl.c
@@ -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 */
diff --git a/drivers/gpu/drm/msm/dp/dp_link.c b/drivers/gpu/drm/msm/dp/dp_link.c
index 98427d45e9a7..a0015b9e79eb 100644
--- a/drivers/gpu/drm/msm/dp/dp_link.c
+++ b/drivers/gpu/drm/msm/dp/dp_link.c
@@ -1179,6 +1179,9 @@ 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:
@@ -1196,12 +1199,13 @@ 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;
}
--
2.35.3