From: Maxime Ripard Date: Wed, 7 Jul 2021 09:51:12 +0000 (+0200) Subject: drm/vc4: hdmi: Only call into DRM framework if registered X-Git-Tag: v5.15~303^2~28^2~7 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=44fe9f90eb9d2533d049b4ba09540eed6cad9f49;p=platform%2Fkernel%2Flinux-starfive.git drm/vc4: hdmi: Only call into DRM framework if registered 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 Reviewed-by: Dave Stevenson Link: https://patchwork.freedesktop.org/patch/msgid/20210707095112.1469670-4-maxime@cerno.tech --- diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c index 7f384b7..e4fcc10 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;