diff options
Diffstat (limited to 'target/linux/bcm27xx/patches-5.15/950-0021-drm-vc4-hdmi-Actually-check-for-the-connector-status.patch')
| -rw-r--r-- | target/linux/bcm27xx/patches-5.15/950-0021-drm-vc4-hdmi-Actually-check-for-the-connector-status.patch | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/target/linux/bcm27xx/patches-5.15/950-0021-drm-vc4-hdmi-Actually-check-for-the-connector-status.patch b/target/linux/bcm27xx/patches-5.15/950-0021-drm-vc4-hdmi-Actually-check-for-the-connector-status.patch new file mode 100644 index 0000000000..44e4d66cc3 --- /dev/null +++ b/target/linux/bcm27xx/patches-5.15/950-0021-drm-vc4-hdmi-Actually-check-for-the-connector-status.patch @@ -0,0 +1,60 @@ +From b30b747d76946fb176bb4b044c830415d551b7bb Mon Sep 17 00:00:00 2001 +From: Maxime Ripard <maxime@cerno.tech> +Date: Thu, 19 Aug 2021 13:50:12 +0200 +Subject: [PATCH] drm/vc4: hdmi: Actually check for the connector + status in hotplug + +The drm_helper_hpd_irq_event() documentation states that this function +is "useful for drivers which can't or don't track hotplug interrupts for +each connector." and that "Drivers which support hotplug interrupts for +each connector individually and which have a more fine-grained detect +logic should bypass this code and directly call +drm_kms_helper_hotplug_event()". This is thus what we ended-up doing. + +However, what this actually means, and is further explained in the +drm_kms_helper_hotplug_event() documentation, is that +drm_kms_helper_hotplug_event() should be called by drivers that can +track the connection status change, and if it has changed we should call +that function. + +This underlying expectation we failed to provide is that the caller of +drm_kms_helper_hotplug_event() should call drm_helper_probe_detect() to +probe the new status of the connector. + +Since we didn't do it, it meant that even though we were sending the +notification to user-space and the DRM clients that something changed we +never probed or updated our internal connector status ourselves. + +This went mostly unnoticed since the detect callback usually doesn't +have any side-effect. Also, if we were using the DRM fbdev emulation +(which is a DRM client), or any user-space application that can deal +with hotplug events, chances are they would react to the hotplug event +by probing the connector status eventually. + +However, now that we have to enable the scrambler in detect() if it was +enabled it has a side effect, and an application such as Kodi or +modetest doesn't deal with hotplug events. This resulted with a black +screen when Kodi or modetest was running when a screen was disconnected +and then reconnected, or switched off and on. + +Signed-off-by: Maxime Ripard <maxime@cerno.tech> +--- + drivers/gpu/drm/vc4/vc4_hdmi.c | 5 +++-- + 1 file changed, 3 insertions(+), 2 deletions(-) + +--- a/drivers/gpu/drm/vc4/vc4_hdmi.c ++++ b/drivers/gpu/drm/vc4/vc4_hdmi.c +@@ -1792,10 +1792,11 @@ static void vc4_hdmi_audio_exit(struct v + static irqreturn_t vc4_hdmi_hpd_irq_thread(int irq, void *priv) + { + struct vc4_hdmi *vc4_hdmi = priv; +- struct drm_device *dev = vc4_hdmi->connector.dev; ++ struct drm_connector *connector = &vc4_hdmi->connector; ++ struct drm_device *dev = connector->dev; + + if (dev && dev->registered) +- drm_kms_helper_hotplug_event(dev); ++ drm_connector_helper_hpd_irq_event(connector); + + return IRQ_HANDLED; + } |