From: Hans Verkuil <hans.verkuil@xxxxxxxxx>
If aux->transfer == NULL, then just return without doing
anything. In that case the function is likely called for
a non-(e)DP connector.
This never happened for the i915 driver, but the nouveau and amdgpu
drivers need this check.
The alternative would be to add this check in those drivers before
every drm_dp_cec call, but it makes sense to check it in the
drm_dp_cec functions to prevent a kernel oops.
Signed-off-by: Hans Verkuil <hans.verkuil at cisco.com>
---
drivers/gpu/drm/drm_dp_cec.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/drivers/gpu/drm/drm_dp_cec.c b/drivers/gpu/drm/drm_dp_cec.c
index 988513346e9c..1407b13a8d5d 100644
--- a/drivers/gpu/drm/drm_dp_cec.c
+++ b/drivers/gpu/drm/drm_dp_cec.c
@@ -238,6 +238,10 @@ void drm_dp_cec_irq(struct drm_dp_aux *aux)
u8 cec_irq;
int ret;
+ /* No transfer function was set, so not a DP connector */
+ if (!aux->transfer)
+ return;
+
mutex_lock(&aux->cec.lock);
if (!aux->cec.adap)
goto unlock;
@@ -293,6 +297,10 @@ void drm_dp_cec_set_edid(struct drm_dp_aux *aux, const struct edid *edid)
unsigned int num_las = 1;
u8 cap;
+ /* No transfer function was set, so not a DP connector */
+ if (!aux->transfer)
+ return;
+
#ifndef CONFIG_MEDIA_CEC_RC
/*
* CEC_CAP_RC is part of CEC_CAP_DEFAULTS, but it is stripped by
@@ -361,6 +369,10 @@ EXPORT_SYMBOL(drm_dp_cec_set_edid);
*/
void drm_dp_cec_unset_edid(struct drm_dp_aux *aux)
{
+ /* No transfer function was set, so not a DP connector */
+ if (!aux->transfer)
+ return;
+
cancel_delayed_work_sync(&aux->cec.unregister_work);
mutex_lock(&aux->cec.lock);
@@ -404,6 +416,8 @@ void drm_dp_cec_register_connector(struct drm_dp_aux *aux, const char *name,
struct device *parent)
{
WARN_ON(aux->cec.adap);
+ if (WARN_ON(!aux->transfer))
+ return;
aux->cec.name = name;
aux->cec.parent = parent;
INIT_DELAYED_WORK(&aux->cec.unregister_work,
--
2.18.0
