From: Maxime Ripard <maxime@cerno.tech>
To: dri-devel@lists.freedesktop.org,
Daniel Vetter <daniel.vetter@intel.com>,
David Airlie <airlied@linux.ie>,
Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
Thomas Zimmermann <tzimmermann@suse.de>,
Maxime Ripard <maxime@cerno.tech>
Cc: Emma Anholt <emma@anholt.net>,
Hans Verkuil <hans.verkuil@cisco.com>,
Daniel Vetter <daniel@ffwll.ch>,
linux-kernel@vger.kernel.org,
linux-rpi-kernel@lists.infradead.org,
bcm-kernel-feedback-list@broadcom.com,
Dave Stevenson <dave.stevenson@raspberrypi.com>,
Phil Elwell <phil@raspberrypi.com>,
Tim Gover <tim.gover@raspberrypi.com>,
Dom Cobley <dom@raspberrypi.com>,
Maxime Ripard <mripard@kernel.org>,
Nicolas Saenz Julienne <nsaenz@kernel.org>
Subject: [PATCH 3/3] drm/vc4: hdmi: Only call into DRM framework if registered
Date: Wed, 7 Jul 2021 11:51:12 +0200 [thread overview]
Message-ID: <20210707095112.1469670-4-maxime@cerno.tech> (raw)
In-Reply-To: <20210707095112.1469670-1-maxime@cerno.tech>
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 --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;
--
2.31.1
next prev parent reply other threads:[~2021-07-07 9:51 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-07 9:51 [PATCH 0/3] drm/vc4: hdmi: Interrupt fixes Maxime Ripard
2021-07-07 9:51 ` [PATCH 1/3] drm/vc4: hdmi: Drop devm interrupt handler for CEC interrupts Maxime Ripard
2021-07-07 9:51 ` [PATCH 2/3] drm/vc4: hdmi: Drop devm interrupt handler for hotplug interrupts Maxime Ripard
2021-07-07 9:51 ` Maxime Ripard [this message]
2021-07-07 10:05 ` [PATCH 0/3] drm/vc4: hdmi: Interrupt fixes Dave Stevenson
2021-07-15 8:50 ` Maxime Ripard
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