drm_dp_cec: check that aux has a transfer function (5ce70c79) · Commits · 戴 / test

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

drivers/gpu/drm/drm_dp_cec.c

+14 −0

Original line number	Diff line number	Diff line
		@@ -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,

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