This is a note to let you know that I've just added the patch titled drm/msm/dp: dp_link_parse_sink_count() return immediately if aux read failed to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: drm-msm-dp-dp_link_parse_sink_count-return-immediate.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 3de4524eb34b7db46474a1dfd6e416284f7198c7 Author: Kuogee Hsieh <quic_khsieh@xxxxxxxxxxx> Date: Wed Dec 8 09:41:02 2021 -0800 drm/msm/dp: dp_link_parse_sink_count() return immediately if aux read failed [ Upstream commit f61550b3864b9578527c28cf9c465316ac1566e1 ] Add checking aux read/write status at both dp_link_parse_sink_count() and dp_link_parse_sink_status_filed() to avoid long timeout delay if dp aux read/write failed at timeout due to cable unplugged. Changes in V4: -- split this patch as stand alone patch Changes in v5: -- rebase on msm-next branch Signed-off-by: Kuogee Hsieh <quic_khsieh@xxxxxxxxxxx> Reviewed-by: Stephen Boyd <swboyd@xxxxxxxxxxxx> Tested-by: Stephen Boyd <swboyd@xxxxxxxxxxxx> Link: https://lore.kernel.org/r/1638985262-2072-1-git-send-email-quic_khsieh@xxxxxxxxxxx Signed-off-by: Rob Clark <robdclark@xxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c index a66ee63253a3..32b8dbb917bf 100644 --- a/drivers/gpu/drm/msm/dp/dp_display.c +++ b/drivers/gpu/drm/msm/dp/dp_display.c @@ -712,9 +712,15 @@ static int dp_irq_hpd_handle(struct dp_display_private *dp, u32 data) return 0; } - ret = dp_display_usbpd_attention_cb(&dp->pdev->dev); - if (ret == -ECONNRESET) { /* cable unplugged */ - dp->core_initialized = false; + /* + * dp core (ahb/aux clks) must be initialized before + * irq_hpd be handled + */ + if (dp->core_initialized) { + ret = dp_display_usbpd_attention_cb(&dp->pdev->dev); + if (ret == -ECONNRESET) { /* cable unplugged */ + dp->core_initialized = false; + } } DRM_DEBUG_DP("hpd_state=%d\n", state); diff --git a/drivers/gpu/drm/msm/dp/dp_link.c b/drivers/gpu/drm/msm/dp/dp_link.c index a5bdfc5029de..d4d31e5bda07 100644 --- a/drivers/gpu/drm/msm/dp/dp_link.c +++ b/drivers/gpu/drm/msm/dp/dp_link.c @@ -737,18 +737,25 @@ static int dp_link_parse_sink_count(struct dp_link *dp_link) return 0; } -static void dp_link_parse_sink_status_field(struct dp_link_private *link) +static int dp_link_parse_sink_status_field(struct dp_link_private *link) { int len = 0; link->prev_sink_count = link->dp_link.sink_count; - dp_link_parse_sink_count(&link->dp_link); + len = dp_link_parse_sink_count(&link->dp_link); + if (len < 0) { + DRM_ERROR("DP parse sink count failed\n"); + return len; + } len = drm_dp_dpcd_read_link_status(link->aux, link->link_status); - if (len < DP_LINK_STATUS_SIZE) + if (len < DP_LINK_STATUS_SIZE) { DRM_ERROR("DP link status read failed\n"); - dp_link_parse_request(link); + return len; + } + + return dp_link_parse_request(link); } /** @@ -1023,7 +1030,9 @@ int dp_link_process_request(struct dp_link *dp_link) dp_link_reset_data(link); - dp_link_parse_sink_status_field(link); + ret = dp_link_parse_sink_status_field(link); + if (ret) + return ret; if (link->request.test_requested == DP_TEST_LINK_EDID_READ) { dp_link->sink_request |= DP_TEST_LINK_EDID_READ;