[PATCH 1/2] drm/msm/dp: service only one irq_hpd if there are multiple irq_hpd pending

From: Kuogee Hsieh
Date: Fri Apr 16 2021 - 16:28:19 EST


Some dongle may generate more than one irq_hpd events in a short period of
time. This patch will treat those irq_hpd events as single one and service
only one irq_hpd event.

Signed-off-by: Kuogee Hsieh <khsieh@xxxxxxxxxxxxxx>
---
drivers/gpu/drm/msm/dp/dp_display.c | 9 +++++++++
1 file changed, 9 insertions(+)

diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
index 5a39da6..0a7d383 100644
--- a/drivers/gpu/drm/msm/dp/dp_display.c
+++ b/drivers/gpu/drm/msm/dp/dp_display.c
@@ -707,6 +707,9 @@ static int dp_irq_hpd_handle(struct dp_display_private *dp, u32 data)
return 0;
}

+ /* only handle first irq_hpd in case of multiple irs_hpd pending */
+ dp_del_event(dp, EV_IRQ_HPD_INT);
+
ret = dp_display_usbpd_attention_cb(&dp->pdev->dev);
if (ret == -ECONNRESET) { /* cable unplugged */
dp->core_initialized = false;
@@ -1300,6 +1303,9 @@ static int dp_pm_suspend(struct device *dev)
/* host_init will be called at pm_resume */
dp->core_initialized = false;

+ /* system suspended, delete pending irq_hdps */
+ dp_del_event(dp, EV_IRQ_HPD_INT);
+
mutex_unlock(&dp->event_mutex);

return 0;
@@ -1496,6 +1502,9 @@ int msm_dp_display_disable(struct msm_dp *dp, struct drm_encoder *encoder)
/* stop sentinel checking */
dp_del_event(dp_display, EV_DISCONNECT_PENDING_TIMEOUT);

+ /* link is down, delete pending irq_hdps */
+ dp_del_event(dp_display, EV_IRQ_HPD_INT);
+
dp_display_disable(dp_display, 0);

rc = dp_display_unprepare(dp);
--
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