The patch below does not apply to the 5.10-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.

thanks,

greg k-h

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

From d9aa6571b28ba0022de1e48801ff03a1854c7ef2 Mon Sep 17 00:00:00 2001

From: Kuogee Hsieh khsieh@codeaurora.org Date: Wed, 21 Apr 2021 16:37:35 -0700 Subject: [PATCH] drm/msm/dp: check sink_count before update is_connected status

Link status is different from display connected status in the case of something like an Apple dongle where the type-c plug can be connected, and therefore the link is connected, but no sink is connected until an HDMI cable is plugged into the dongle. The sink_count of DPCD of dongle will increase to 1 once an HDMI cable is plugged into the dongle so that display connected status will become true. This checking also apply at pm_resume.

Changes in v4: -- none

Fixes: 94e58e2d06e3 ("drm/msm/dp: reset dp controller only at boot up and pm_resume") Reported-by: Stephen Boyd swboyd@chromium.org Reviewed-by: Stephen Boyd swboyd@chromium.org Tested-by: Stephen Boyd swboyd@chromium.org Signed-off-by: Kuogee Hsieh khsieh@codeaurora.org Fixes: 8ede2ecc3e5e ("drm/msm/dp: Add DP compliance tests on Snapdragon Chipsets") Link: https://lore.kernel.org/r/1619048258-8717-2-git-send-email-khsieh@codeaurora... Signed-off-by: Rob Clark robdclark@chromium.org

diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c index 5a39da6e1eaf..0ba71c7a8dd4 100644 --- a/drivers/gpu/drm/msm/dp/dp_display.c +++ b/drivers/gpu/drm/msm/dp/dp_display.c @@ -586,10 +586,8 @@ static int dp_connect_pending_timeout(struct dp_display_private *dp, u32 data) mutex_lock(&dp->event_mutex);

state = dp->hpd_state; - if (state == ST_CONNECT_PENDING) { - dp_display_enable(dp, 0); + if (state == ST_CONNECT_PENDING) dp->hpd_state = ST_CONNECTED; - }

mutex_unlock(&dp->event_mutex);

@@ -669,10 +667,8 @@ static int dp_disconnect_pending_timeout(struct dp_display_private *dp, u32 data mutex_lock(&dp->event_mutex);

state = dp->hpd_state; - if (state == ST_DISCONNECT_PENDING) { - dp_display_disable(dp, 0); + if (state == ST_DISCONNECT_PENDING) dp->hpd_state = ST_DISCONNECTED; - }

mutex_unlock(&dp->event_mutex);

@@ -1272,7 +1268,12 @@ static int dp_pm_resume(struct device *dev)

status = dp_catalog_link_is_connected(dp->catalog);

- if (status) + /* + * can not declared display is connected unless + * HDMI cable is plugged in and sink_count of + * dongle become 1 + */ + if (status && dp->link->sink_count) dp->dp_display.is_connected = true; else dp->dp_display.is_connected = false;