drm_dp_cec: check that aux has a transfer function

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@cisco.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180827075820.41109-2-hverkuil@xs4all.nl
This commit is contained in:
Hans Verkuil 2018-08-27 09:58:16 +02:00
parent 09c4b49457
commit 5ce70c799a
1 changed files with 14 additions and 0 deletions

View File

@ -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,