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[3/3] drm/vc4: hdmi: Only call into DRM framework if registered

Message ID 20210707095112.1469670-4-maxime@cerno.tech (mailing list archive)
State New, archived
Headers show
Series drm/vc4: hdmi: Interrupt fixes | expand

Commit Message

Maxime Ripard July 7, 2021, 9:51 a.m. UTC 
Our hotplug handler will currently call the drm_kms_helper_hotplug_event
every time a hotplug interrupt is called.

However, since the device is registered after all the drivers have
finished their bind callback, we have a window between when we install
our interrupt handler and when drm_dev_register() is eventually called
where our handler can run and call drm_kms_helper_hotplug_event but the
device hasn't been registered yet, causing a null pointer dereference.

Fix this by making sure we only call drm_kms_helper_hotplug_event if our
device has been properly registered.

Fixes: f4790083c7c2 ("drm/vc4: hdmi: Rely on interrupts to handle hotplug")
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
---
 drivers/gpu/drm/vc4/vc4_hdmi.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index 50393a8a42b3..31c28252c5f5 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -1580,7 +1580,7 @@  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;
 
-	if (dev)
+	if (dev && dev->registered)
 		drm_kms_helper_hotplug_event(dev);
 
 	return IRQ_HANDLED;