On Fri, 2018-08-17 at 16:11 +0200, Hans Verkuil wrote:
From: Hans Verkuil hans.verkuil@cisco.com
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.
Could you give a backtrace from where you're hitting this issue with nouveau and amdgpu? It doesn't make a whole ton of sense to have connectors registering DP aux busses if they aren't actually DP, that should probably just be fixed...
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
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;