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Revert "drm/msm/dp: use drm_bridge_hpd_notify() to report HPD status changes"

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This reverts commit e467e0bde8 ("drm/msm/dp: use
drm_bridge_hpd_notify() to report HPD status changes").

The commit changed the way how the MSM DP driver communicates
HPD-related events to the userspace. The mentioned commit made some of
the HPD events being reported earlier. This way userspace starts poking
around. It interacts in a bad way with the dp_bridge_detect and the
driver's state machine, ending up either with the very long delays
during hotplug detection or even inability of the DP driver to report
the display as connected.

A proper fix will involve redesigning of the HPD handling in the MSM DP
driver. It is underway, but it will be intrusive and can not be thought
about as a simple fix for the issue. Thus, revert the offending commit.

Fixes: e467e0bde8 ("drm/msm/dp: use drm_bridge_hpd_notify() to report HPD status changes")
Link: https://gitlab.freedesktop.org/drm/msm/-/issues/50
Reported-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/Zd3YPGmrprxv-N-O@hovoldconsulting.com/
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Tested-by: Paloma Arellano <quic_parellan@quicinc.com>
Tested-by: Johan Hovold <johan+linaro@kernel.org>
Tested-by: Neil Armstrong <neil.armstrong@linaro.org> # on SM8650-HDK
Patchwork: https://patchwork.freedesktop.org/patch/580313/
Link: https://lore.kernel.org/r/20240227220808.50146-1-dmitry.baryshkov@linaro.org
This commit is contained in:
Dmitry Baryshkov
2024-02-28 00:08:08 +02:00
parent 8c7bfd8262
commit 664bad6af3
1 changed files with 18 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files
drivers/gpu/drm/msm/dp/dp_display.c
+18 -2
View File
@@ -329,10 +329,26 @@ static const struct component_ops dp_display_comp_ops = {
.unbind = dp_display_unbind,
};
static void dp_display_send_hpd_event(struct msm_dp *dp_display)
{
struct dp_display_private *dp;
struct drm_connector *connector;
dp = container_of(dp_display, struct dp_display_private, dp_display);
connector = dp->dp_display.connector;
drm_helper_hpd_irq_event(connector->dev);
}
static int dp_display_send_hpd_notification(struct dp_display_private *dp,
bool hpd)
{
struct drm_bridge *bridge = dp->dp_display.bridge;
if ((hpd && dp->dp_display.link_ready) ||
(!hpd && !dp->dp_display.link_ready)) {
drm_dbg_dp(dp->drm_dev, "HPD already %s\n",
(hpd ? "on" : "off"));
return 0;
}
/* reset video pattern flag on disconnect */
if (!hpd) {
@@ -348,7 +364,7 @@ static int dp_display_send_hpd_notification(struct dp_display_private *dp,
drm_dbg_dp(dp->drm_dev, "type=%d hpd=%d\n",
dp->dp_display.connector_type, hpd);
drm_bridge_hpd_notify(bridge, dp->dp_display.link_ready);
dp_display_send_hpd_event(&dp->dp_display);
return 0;
}