The patch below does not apply to the 6.12-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.12.y git checkout FETCH_HEAD git cherry-pick -x df9cf852ca3099feb8fed781bdd5d3863af001c8 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2025022457-capitol-primate-f197@gregkh' --subject-prefix 'PATCH 6.12.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From df9cf852ca3099feb8fed781bdd5d3863af001c8 Mon Sep 17 00:00:00 2001 From: Abhinav Kumar quic_abhinavk@quicinc.com Date: Thu, 6 Feb 2025 11:46:36 -0800 Subject: [PATCH] drm/msm/dp: account for widebus and yuv420 during mode validation

Widebus allows the DP controller to operate in 2 pixel per clock mode. The mode validation logic validates the mode->clock against the max DP pixel clock. However the max DP pixel clock limit assumes widebus is already enabled. Adjust the mode validation logic to only compare the adjusted pixel clock which accounts for widebus against the max DP pixel clock. Also fix the mode validation logic for YUV420 modes as in that case as well, only half the pixel clock is needed.

Cc: stable@vger.kernel.org Fixes: 757a2f36ab09 ("drm/msm/dp: enable widebus feature for display port") Fixes: 6db6e5606576 ("drm/msm/dp: change clock related programming for YUV420 over DP") Reviewed-by: Dmitry Baryshkov dmitry.baryshkov@linaro.org Tested-by: Dale Whinham daleyo@gmail.com Patchwork: https://patchwork.freedesktop.org/patch/635789/ Link: https://lore.kernel.org/r/20250206-dp-widebus-fix-v2-1-cb89a0313286@quicinc.... Signed-off-by: Abhinav Kumar quic_abhinavk@quicinc.com

diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c index d852e7a85334..a129e26c3ddb 100644 --- a/drivers/gpu/drm/msm/dp/dp_display.c +++ b/drivers/gpu/drm/msm/dp/dp_display.c @@ -930,16 +930,17 @@ enum drm_mode_status msm_dp_bridge_mode_valid(struct drm_bridge *bridge, return -EINVAL; }

- if (mode->clock > DP_MAX_PIXEL_CLK_KHZ) - return MODE_CLOCK_HIGH; - msm_dp_display = container_of(dp, struct msm_dp_display_private, msm_dp_display); link_info = &msm_dp_display->panel->link_info;

- if (drm_mode_is_420_only(&dp->connector->display_info, mode) && - msm_dp_display->panel->vsc_sdp_supported) + if ((drm_mode_is_420_only(&dp->connector->display_info, mode) && + msm_dp_display->panel->vsc_sdp_supported) || + msm_dp_wide_bus_available(dp)) mode_pclk_khz /= 2;

+ if (mode_pclk_khz > DP_MAX_PIXEL_CLK_KHZ) + return MODE_CLOCK_HIGH; + mode_bpp = dp->connector->display_info.bpc * num_components; if (!mode_bpp) mode_bpp = default_bpp; diff --git a/drivers/gpu/drm/msm/dp/dp_drm.c b/drivers/gpu/drm/msm/dp/dp_drm.c index d3e241ea6941..16b7913d1eef 100644 --- a/drivers/gpu/drm/msm/dp/dp_drm.c +++ b/drivers/gpu/drm/msm/dp/dp_drm.c @@ -257,7 +257,10 @@ static enum drm_mode_status msm_edp_bridge_mode_valid(struct drm_bridge *bridge, return -EINVAL; }

- if (mode->clock > DP_MAX_PIXEL_CLK_KHZ) + if (msm_dp_wide_bus_available(dp)) + mode_pclk_khz /= 2; + + if (mode_pclk_khz > DP_MAX_PIXEL_CLK_KHZ) return MODE_CLOCK_HIGH;

/*