[PATCH 00/10] drm/connector: add eld_mutex to protect connector->eld

[PATCH 00/10] drm/connector: add eld_mutex to protect connector->eld

[Dmitry Baryshkov]

The connector->eld is accessed by the .get_eld() callback. This access
can collide with the drm_edid_to_eld() updating the data at the same
time. Add drm_connector.eld_mutex to protect the data from concurrenct
access.

The individual drivers were just compile tested. I propose to merge the
drm_connector and bridge drivers through drm-misc, allowing other
maintainers either to ack merging through drm-misc or merging the
drm-misc into their tree and then picking up correcponding patch.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
Dmitry Baryshkov (10):
      drm/connector: add mutex to protect ELD from concurrent access
      drm/bridge: anx7625: use eld_mutex to protect access to connector->eld
      drm/bridge: ite-it66121: use eld_mutex to protect access to connector->eld
      drm/amd/display: use eld_mutex to protect access to connector->eld
      drm/exynos: hdmi: use eld_mutex to protect access to connector->eld
      drm/i915/audio: use eld_mutex to protect access to connector->eld
      drm/msm/dp: use eld_mutex to protect access to connector->eld
      drm/radeon: use eld_mutex to protect access to connector->eld
      drm/sti: hdmi: use eld_mutex to protect access to connector->eld
      drm/vc4: hdmi: use eld_mutex to protect access to connector->eld

 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 2 ++
 drivers/gpu/drm/bridge/analogix/anx7625.c         | 2 ++
 drivers/gpu/drm/bridge/ite-it66121.c              | 2 ++
 drivers/gpu/drm/drm_connector.c                   | 1 +
 drivers/gpu/drm/drm_edid.c                        | 4 ++++
 drivers/gpu/drm/exynos/exynos_hdmi.c              | 2 ++
 drivers/gpu/drm/i915/display/intel_audio.c        | 3 +++
 drivers/gpu/drm/msm/dp/dp_audio.c                 | 2 ++
 drivers/gpu/drm/radeon/radeon_audio.c             | 2 ++
 drivers/gpu/drm/sti/sti_hdmi.c                    | 2 ++
 drivers/gpu/drm/vc4/vc4_hdmi.c                    | 4 ++--
 include/drm/drm_connector.h                       | 5 ++++-
 12 files changed, 28 insertions(+), 3 deletions(-)
---
base-commit: 44cff6c5b0b17a78bc0b30372bcd816cf6dd282a
change-id: 20241201-drm-connector-eld-mutex-8a39a35e9a38

Best regards,
-- 
Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

[PATCH 01/10] drm/connector: add mutex to protect ELD from concurrent access

[Dmitry Baryshkov]

The connector->eld is accessed by the .get_eld() callback. This access
can collide with the drm_edid_to_eld() updating the data at the same
time. Add drm_connector.eld_mutex to protect the data from concurrenct
access. Individual drivers are not updated (to reduce possible issues
while applying the patch), maintainers are to find a best suitable way
to lock that mutex while accessing the ELD data.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
 drivers/gpu/drm/drm_connector.c | 1 +
 drivers/gpu/drm/drm_edid.c      | 4 ++++
 include/drm/drm_connector.h     | 5 ++++-
 3 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
index fc35f47e2849ed6786d6223ac9c69e1c359fc648..bbdaaf7022b62d84594a29f1b60144920903a99a 100644
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -277,6 +277,7 @@ static int __drm_connector_init(struct drm_device *dev,
 	INIT_LIST_HEAD(&connector->probed_modes);
 	INIT_LIST_HEAD(&connector->modes);
 	mutex_init(&connector->mutex);
+	mutex_init(&connector->eld_mutex);
 	mutex_init(&connector->edid_override_mutex);
 	mutex_init(&connector->hdmi.infoframes.lock);
 	connector->edid_blob_ptr = NULL;
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 855beafb76ffbecf5c08d58e2f54bfb76f30b930..f0ca77bd42fd518d505d0db78557e0c8d83efb29 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -5657,6 +5657,8 @@ static void drm_edid_to_eld(struct drm_connector *connector,
 	if (!drm_edid)
 		return;
 
+	mutex_lock(&connector->eld_mutex);
+
 	mnl = get_monitor_name(drm_edid, &eld[DRM_ELD_MONITOR_NAME_STRING]);
 	drm_dbg_kms(connector->dev, "[CONNECTOR:%d:%s] ELD monitor %s\n",
 		    connector->base.id, connector->name,
@@ -5717,6 +5719,8 @@ static void drm_edid_to_eld(struct drm_connector *connector,
 	drm_dbg_kms(connector->dev, "[CONNECTOR:%d:%s] ELD size %d, SAD count %d\n",
 		    connector->base.id, connector->name,
 		    drm_eld_size(eld), total_sad_count);
+
+	mutex_unlock(&connector->eld_mutex);
 }
 
 static int _drm_edid_to_sad(const struct drm_edid *drm_edid,
diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
index e3fa43291f449d70f3b92a00985336c4f2237bc6..1e2b25e204cb523d61d30f5409faa059bf2b86eb 100644
--- a/include/drm/drm_connector.h
+++ b/include/drm/drm_connector.h
@@ -2001,8 +2001,11 @@ struct drm_connector {
 	struct drm_encoder *encoder;
 
 #define MAX_ELD_BYTES	128
-	/** @eld: EDID-like data, if present */
+	/** @eld: EDID-like data, if present, protected by @eld_mutex */
 	uint8_t eld[MAX_ELD_BYTES];
+	/** @eld_mutex: protection for concurrenct access to @eld */
+	struct mutex eld_mutex;
+
 	/** @latency_present: AV delay info from ELD, if found */
 	bool latency_present[2];
 	/**

-- 
2.39.5

Re: [PATCH 01/10] drm/connector: add mutex to protect ELD from concurrent access

[Jani Nikula]

On Sun, 01 Dec 2024, Dmitry Baryshkov <dmitry.baryshkov@linaro.org> wrote:
> The connector->eld is accessed by the .get_eld() callback. This access
> can collide with the drm_edid_to_eld() updating the data at the same
> time. Add drm_connector.eld_mutex to protect the data from concurrenct
> access. Individual drivers are not updated (to reduce possible issues
> while applying the patch), maintainers are to find a best suitable way
> to lock that mutex while accessing the ELD data.

Missed clear_eld().

BR,
Jani.

>
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> ---
>  drivers/gpu/drm/drm_connector.c | 1 +
>  drivers/gpu/drm/drm_edid.c      | 4 ++++
>  include/drm/drm_connector.h     | 5 ++++-
>  3 files changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
> index fc35f47e2849ed6786d6223ac9c69e1c359fc648..bbdaaf7022b62d84594a29f1b60144920903a99a 100644
> --- a/drivers/gpu/drm/drm_connector.c
> +++ b/drivers/gpu/drm/drm_connector.c
> @@ -277,6 +277,7 @@ static int __drm_connector_init(struct drm_device *dev,
>  	INIT_LIST_HEAD(&connector->probed_modes);
>  	INIT_LIST_HEAD(&connector->modes);
>  	mutex_init(&connector->mutex);
> +	mutex_init(&connector->eld_mutex);
>  	mutex_init(&connector->edid_override_mutex);
>  	mutex_init(&connector->hdmi.infoframes.lock);
>  	connector->edid_blob_ptr = NULL;
> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
> index 855beafb76ffbecf5c08d58e2f54bfb76f30b930..f0ca77bd42fd518d505d0db78557e0c8d83efb29 100644
> --- a/drivers/gpu/drm/drm_edid.c
> +++ b/drivers/gpu/drm/drm_edid.c
> @@ -5657,6 +5657,8 @@ static void drm_edid_to_eld(struct drm_connector *connector,
>  	if (!drm_edid)
>  		return;
>  
> +	mutex_lock(&connector->eld_mutex);
> +
>  	mnl = get_monitor_name(drm_edid, &eld[DRM_ELD_MONITOR_NAME_STRING]);
>  	drm_dbg_kms(connector->dev, "[CONNECTOR:%d:%s] ELD monitor %s\n",
>  		    connector->base.id, connector->name,
> @@ -5717,6 +5719,8 @@ static void drm_edid_to_eld(struct drm_connector *connector,
>  	drm_dbg_kms(connector->dev, "[CONNECTOR:%d:%s] ELD size %d, SAD count %d\n",
>  		    connector->base.id, connector->name,
>  		    drm_eld_size(eld), total_sad_count);
> +
> +	mutex_unlock(&connector->eld_mutex);
>  }
>  
>  static int _drm_edid_to_sad(const struct drm_edid *drm_edid,
> diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
> index e3fa43291f449d70f3b92a00985336c4f2237bc6..1e2b25e204cb523d61d30f5409faa059bf2b86eb 100644
> --- a/include/drm/drm_connector.h
> +++ b/include/drm/drm_connector.h
> @@ -2001,8 +2001,11 @@ struct drm_connector {
>  	struct drm_encoder *encoder;
>  
>  #define MAX_ELD_BYTES	128
> -	/** @eld: EDID-like data, if present */
> +	/** @eld: EDID-like data, if present, protected by @eld_mutex */
>  	uint8_t eld[MAX_ELD_BYTES];
> +	/** @eld_mutex: protection for concurrenct access to @eld */
> +	struct mutex eld_mutex;
> +
>  	/** @latency_present: AV delay info from ELD, if found */
>  	bool latency_present[2];
>  	/**

-- 
Jani Nikula, Intel

[PATCH 02/10] drm/bridge: anx7625: use eld_mutex to protect access to connector->eld

[Dmitry Baryshkov]

Reading access to connector->eld can happen at the same time the
drm_edid_to_eld() updates the data. Take the newly added eld_mutex in
order to protect connector->eld from concurrent access.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
 drivers/gpu/drm/bridge/analogix/anx7625.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/bridge/analogix/anx7625.c b/drivers/gpu/drm/bridge/analogix/anx7625.c
index a2675b121fe44b96945f34215fd900f35bfde43a..c036bbc92ba96ec4663c55cca091cd5da9f6d271 100644
--- a/drivers/gpu/drm/bridge/analogix/anx7625.c
+++ b/drivers/gpu/drm/bridge/analogix/anx7625.c
@@ -2002,8 +2002,10 @@ static int anx7625_audio_get_eld(struct device *dev, void *data,
 		memset(buf, 0, len);
 	} else {
 		dev_dbg(dev, "audio copy eld\n");
+		mutex_lock(&ctx->connector->eld_mutex);
 		memcpy(buf, ctx->connector->eld,
 		       min(sizeof(ctx->connector->eld), len));
+		mutex_unlock(&ctx->connector->eld_mutex);
 	}
 
 	return 0;

-- 
2.39.5

[PATCH 03/10] drm/bridge: ite-it66121: use eld_mutex to protect access to connector->eld

[Dmitry Baryshkov]

Reading access to connector->eld can happen at the same time the
drm_edid_to_eld() updates the data. Take the newly added eld_mutex in
order to protect connector->eld from concurrent access.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
 drivers/gpu/drm/bridge/ite-it66121.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/bridge/ite-it66121.c b/drivers/gpu/drm/bridge/ite-it66121.c
index 35ae3f0e8f51f768229e055a086b53a419ffcd9f..940083e5d2ddbfc56f14e2bdc6ddd0b9dd50b1f8 100644
--- a/drivers/gpu/drm/bridge/ite-it66121.c
+++ b/drivers/gpu/drm/bridge/ite-it66121.c
@@ -1450,8 +1450,10 @@ static int it66121_audio_get_eld(struct device *dev, void *data,
 		dev_dbg(dev, "No connector present, passing empty EDID data");
 		memset(buf, 0, len);
 	} else {
+		mutex_lock(&ctx->connector->eld_mutex);
 		memcpy(buf, ctx->connector->eld,
 		       min(sizeof(ctx->connector->eld), len));
+		mutex_unlock(&ctx->connector->eld_mutex);
 	}
 	mutex_unlock(&ctx->lock);
 

-- 
2.39.5

[PATCH 04/10] drm/amd/display: use eld_mutex to protect access to connector->eld

[Dmitry Baryshkov]

Reading access to connector->eld can happen at the same time the
drm_edid_to_eld() updates the data. Take the newly added eld_mutex in
order to protect connector->eld from concurrent access.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index a0bcc62f280f8e80f5d174cd2f567a8ec616e54f..2843283375551b0b85f5f897acdb2aeab652892c 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -1037,8 +1037,10 @@ static int amdgpu_dm_audio_component_get_eld(struct device *kdev, int port,
 			continue;
 
 		*enabled = true;
+		mutex_lock(&connector->eld_mutex);
 		ret = drm_eld_size(connector->eld);
 		memcpy(buf, connector->eld, min(max_bytes, ret));
+		mutex_unlock(&connector->eld_mutex);
 
 		break;
 	}

-- 
2.39.5

[PATCH 05/10] drm/exynos: hdmi: use eld_mutex to protect access to connector->eld

[Dmitry Baryshkov]

Reading access to connector->eld can happen at the same time the
drm_edid_to_eld() updates the data. Take the newly added eld_mutex in
order to protect connector->eld from concurrent access.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
 drivers/gpu/drm/exynos/exynos_hdmi.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/exynos/exynos_hdmi.c b/drivers/gpu/drm/exynos/exynos_hdmi.c
index c9d4b9146df95bb46cb6bea4849c331616c2b463..6fc537c9048f5c8e57e30f083121c9aea6b99a5f 100644
--- a/drivers/gpu/drm/exynos/exynos_hdmi.c
+++ b/drivers/gpu/drm/exynos/exynos_hdmi.c
@@ -1648,7 +1648,9 @@ static int hdmi_audio_get_eld(struct device *dev, void *data, uint8_t *buf,
 	struct hdmi_context *hdata = dev_get_drvdata(dev);
 	struct drm_connector *connector = &hdata->connector;
 
+	mutex_lock(&connector->eld_mutex);
 	memcpy(buf, connector->eld, min(sizeof(connector->eld), len));
+	mutex_unlock(&connector->eld_mutex);
 
 	return 0;
 }

-- 
2.39.5

[PATCH 06/10] drm/i915/audio: use eld_mutex to protect access to connector->eld

[Dmitry Baryshkov]

Reading access to connector->eld can happen at the same time the
drm_edid_to_eld() updates the data. Take the newly added eld_mutex in
order to protect connector->eld from concurrent access.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
 drivers/gpu/drm/i915/display/intel_audio.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_audio.c b/drivers/gpu/drm/i915/display/intel_audio.c
index 32aa9ec1a204d2ecde46cad36598aa768a3af671..3902ab8431139c3ff4dc17b841d94b6d3241dec3 100644
--- a/drivers/gpu/drm/i915/display/intel_audio.c
+++ b/drivers/gpu/drm/i915/display/intel_audio.c
@@ -699,10 +699,12 @@ bool intel_audio_compute_config(struct intel_encoder *encoder,
 	const struct drm_display_mode *adjusted_mode =
 		&crtc_state->hw.adjusted_mode;
 
+	mutex_lock(&connector->eld_mutex);
 	if (!connector->eld[0]) {
 		drm_dbg_kms(&i915->drm,
 			    "Bogus ELD on [CONNECTOR:%d:%s]\n",
 			    connector->base.id, connector->name);
+		mutex_unlock(&connector->eld_mutex);
 		return false;
 	}
 
@@ -710,6 +712,7 @@ bool intel_audio_compute_config(struct intel_encoder *encoder,
 	memcpy(crtc_state->eld, connector->eld, sizeof(crtc_state->eld));
 
 	crtc_state->eld[6] = drm_av_sync_delay(connector, adjusted_mode) / 2;
+	mutex_unlock(&connector->eld_mutex);
 
 	return true;
 }

-- 
2.39.5

Re: [PATCH 06/10] drm/i915/audio: use eld_mutex to protect access to connector->eld

[Jani Nikula]

On Sun, 01 Dec 2024, Dmitry Baryshkov <dmitry.baryshkov@linaro.org> wrote:
> Reading access to connector->eld can happen at the same time the
> drm_edid_to_eld() updates the data. Take the newly added eld_mutex in
> order to protect connector->eld from concurrent access.
>
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

Reviewed-by: Jani Nikula <jani.nikula@intel.com>

and

Acked-by: Jani Nikula <jani.nikula@intel.com>

for merging via whichever tree you find best.



> ---
>  drivers/gpu/drm/i915/display/intel_audio.c | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_audio.c b/drivers/gpu/drm/i915/display/intel_audio.c
> index 32aa9ec1a204d2ecde46cad36598aa768a3af671..3902ab8431139c3ff4dc17b841d94b6d3241dec3 100644
> --- a/drivers/gpu/drm/i915/display/intel_audio.c
> +++ b/drivers/gpu/drm/i915/display/intel_audio.c
> @@ -699,10 +699,12 @@ bool intel_audio_compute_config(struct intel_encoder *encoder,
>  	const struct drm_display_mode *adjusted_mode =
>  		&crtc_state->hw.adjusted_mode;
>  
> +	mutex_lock(&connector->eld_mutex);
>  	if (!connector->eld[0]) {
>  		drm_dbg_kms(&i915->drm,
>  			    "Bogus ELD on [CONNECTOR:%d:%s]\n",
>  			    connector->base.id, connector->name);
> +		mutex_unlock(&connector->eld_mutex);
>  		return false;
>  	}
>  
> @@ -710,6 +712,7 @@ bool intel_audio_compute_config(struct intel_encoder *encoder,
>  	memcpy(crtc_state->eld, connector->eld, sizeof(crtc_state->eld));
>  
>  	crtc_state->eld[6] = drm_av_sync_delay(connector, adjusted_mode) / 2;
> +	mutex_unlock(&connector->eld_mutex);
>  
>  	return true;
>  }

-- 
Jani Nikula, Intel

[PATCH 07/10] drm/msm/dp: use eld_mutex to protect access to connector->eld

[Dmitry Baryshkov]

Reading access to connector->eld can happen at the same time the
drm_edid_to_eld() updates the data. Take the newly added eld_mutex in
order to protect connector->eld from concurrent access.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
 drivers/gpu/drm/msm/dp/dp_audio.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/msm/dp/dp_audio.c b/drivers/gpu/drm/msm/dp/dp_audio.c
index a599fc5d63c524474276f5db98b05c7c512f332a..61952a0c49861efcb5e7c0884fcb85c040daf9ce 100644
--- a/drivers/gpu/drm/msm/dp/dp_audio.c
+++ b/drivers/gpu/drm/msm/dp/dp_audio.c
@@ -414,8 +414,10 @@ static int dp_audio_get_eld(struct device *dev,
 		return -ENODEV;
 	}
 
+	mutex_lock(&dp_display->connector->eld_mutex);
 	memcpy(buf, dp_display->connector->eld,
 		min(sizeof(dp_display->connector->eld), len));
+	mutex_unlock(&dp_display->connector->eld_mutex);
 
 	return 0;
 }

-- 
2.39.5

Re: [PATCH 07/10] drm/msm/dp: use eld_mutex to protect access to connector->eld

[Abhinav Kumar]

On 11/30/2024 3:55 PM, Dmitry Baryshkov wrote:
> Reading access to connector->eld can happen at the same time the
> drm_edid_to_eld() updates the data. Take the newly added eld_mutex in
> order to protect connector->eld from concurrent access.
> 
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> ---
>   drivers/gpu/drm/msm/dp/dp_audio.c | 2 ++
>   1 file changed, 2 insertions(+)
> 

Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>

Re: [PATCH 07/10] drm/msm/dp: use eld_mutex to protect access to connector->eld

[Dmitry Baryshkov]

On Mon, Dec 02, 2024 at 07:27:45PM -0800, Abhinav Kumar wrote:
> 
> 
> On 11/30/2024 3:55 PM, Dmitry Baryshkov wrote:
> > Reading access to connector->eld can happen at the same time the
> > drm_edid_to_eld() updates the data. Take the newly added eld_mutex in
> > order to protect connector->eld from concurrent access.
> > 
> > Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> > ---
> >   drivers/gpu/drm/msm/dp/dp_audio.c | 2 ++
> >   1 file changed, 2 insertions(+)
> > 
> 
> Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>

Ack to merge through drm-misc?

-- 
With best wishes
Dmitry

Re: [PATCH 07/10] drm/msm/dp: use eld_mutex to protect access to connector->eld

[Abhinav Kumar]

On 12/3/2024 5:58 AM, Dmitry Baryshkov wrote:
> On Mon, Dec 02, 2024 at 07:27:45PM -0800, Abhinav Kumar wrote:
>>
>>
>> On 11/30/2024 3:55 PM, Dmitry Baryshkov wrote:
>>> Reading access to connector->eld can happen at the same time the
>>> drm_edid_to_eld() updates the data. Take the newly added eld_mutex in
>>> order to protect connector->eld from concurrent access.
>>>
>>> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
>>> ---
>>>    drivers/gpu/drm/msm/dp/dp_audio.c | 2 ++
>>>    1 file changed, 2 insertions(+)
>>>
>>
>> Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
> 
> Ack to merge through drm-misc?
> 

Yes,

Acked-by: Abhinav Kumar <quic_abhinavk@quicinc.com>

[PATCH 08/10] drm/radeon: use eld_mutex to protect access to connector->eld

[Dmitry Baryshkov]

Reading access to connector->eld can happen at the same time the
drm_edid_to_eld() updates the data. Take the newly added eld_mutex in
order to protect connector->eld from concurrent access.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
 drivers/gpu/drm/radeon/radeon_audio.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/radeon/radeon_audio.c b/drivers/gpu/drm/radeon/radeon_audio.c
index 47aa06a9a94221555a4828f41a57cbe03d637ee1..547d8f420669cdb949ffebd0677ddb8cc3c25812 100644
--- a/drivers/gpu/drm/radeon/radeon_audio.c
+++ b/drivers/gpu/drm/radeon/radeon_audio.c
@@ -771,8 +771,10 @@ static int radeon_audio_component_get_eld(struct device *kdev, int port,
 		if (!connector)
 			continue;
 		*enabled = true;
+		mutex_lock(&connector->eld_mutex);
 		ret = drm_eld_size(connector->eld);
 		memcpy(buf, connector->eld, min(max_bytes, ret));
+		mutex_unlock(&connector->eld_mutex);
 		break;
 	}
 

-- 
2.39.5

[PATCH 09/10] drm/sti: hdmi: use eld_mutex to protect access to connector->eld

[Dmitry Baryshkov]

Reading access to connector->eld can happen at the same time the
drm_edid_to_eld() updates the data. Take the newly added eld_mutex in
order to protect connector->eld from concurrent access.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
 drivers/gpu/drm/sti/sti_hdmi.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/sti/sti_hdmi.c b/drivers/gpu/drm/sti/sti_hdmi.c
index 847470f747c0efad61c2ebdc3fb3746a7a13a863..3c8f3532c79723e7b1a720c855c90e40584cc6ca 100644
--- a/drivers/gpu/drm/sti/sti_hdmi.c
+++ b/drivers/gpu/drm/sti/sti_hdmi.c
@@ -1225,7 +1225,9 @@ static int hdmi_audio_get_eld(struct device *dev, void *data, uint8_t *buf, size
 	struct drm_connector *connector = hdmi->drm_connector;
 
 	DRM_DEBUG_DRIVER("\n");
+	mutex_lock(&connector->eld_mutex);
 	memcpy(buf, connector->eld, min(sizeof(connector->eld), len));
+	mutex_unlock(&connector->eld_mutex);
 
 	return 0;
 }

-- 
2.39.5

Re: [PATCH 09/10] drm/sti: hdmi: use eld_mutex to protect access to connector->eld

[Raphaël Gallais-Pou]

Le 01/12/2024 à 00:55, Dmitry Baryshkov a écrit :
> Reading access to connector->eld can happen at the same time the
> drm_edid_to_eld() updates the data. Take the newly added eld_mutex in
> order to protect connector->eld from concurrent access.
> 
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

Hi Dmitry,

Acked-by: Raphael Gallais-Pou <rgallaispou@gmail.com>

Thanks,
Raphaël
> ---
>   drivers/gpu/drm/sti/sti_hdmi.c | 2 ++
>   1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/gpu/drm/sti/sti_hdmi.c b/drivers/gpu/drm/sti/sti_hdmi.c
> index 847470f747c0efad61c2ebdc3fb3746a7a13a863..3c8f3532c79723e7b1a720c855c90e40584cc6ca 100644
> --- a/drivers/gpu/drm/sti/sti_hdmi.c
> +++ b/drivers/gpu/drm/sti/sti_hdmi.c
> @@ -1225,7 +1225,9 @@ static int hdmi_audio_get_eld(struct device *dev, void *data, uint8_t *buf, size
>   	struct drm_connector *connector = hdmi->drm_connector;
>   
>   	DRM_DEBUG_DRIVER("\n");
> +	mutex_lock(&connector->eld_mutex);
>   	memcpy(buf, connector->eld, min(sizeof(connector->eld), len));
> +	mutex_unlock(&connector->eld_mutex);
>   
>   	return 0;
>   }
> 

[PATCH 10/10] drm/vc4: hdmi: use eld_mutex to protect access to connector->eld

[Dmitry Baryshkov]

Reading access to connector->eld can happen at the same time the
drm_edid_to_eld() updates the data. Take the newly added eld_mutex in
order to protect connector->eld from concurrent access.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
 drivers/gpu/drm/vc4/vc4_hdmi.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index b9fc4d981cf4d682bedd978795cf7284d2650e74..7295834e75fb1ab0cd241ed274e675567e66870b 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -2221,9 +2221,9 @@ static int vc4_hdmi_audio_get_eld(struct device *dev, void *data,
 	struct vc4_hdmi *vc4_hdmi = dev_get_drvdata(dev);
 	struct drm_connector *connector = &vc4_hdmi->connector;
 
-	mutex_lock(&vc4_hdmi->mutex);
+	mutex_lock(&connector->eld_mutex);
 	memcpy(buf, connector->eld, min(sizeof(connector->eld), len));
-	mutex_unlock(&vc4_hdmi->mutex);
+	mutex_unlock(&connector->eld_mutex);
 
 	return 0;
 }

-- 
2.39.5

Re: [PATCH 00/10] drm/connector: add eld_mutex to protect connector->eld

[Maxime Ripard]

On Sun, 1 Dec 2024 01:55:17 +0200, Dmitry Baryshkov wrote:
> The connector->eld is accessed by the .get_eld() callback. This access
> can collide with the drm_edid_to_eld() updating the data at the same
> time. Add drm_connector.eld_mutex to protect the data from concurrenct
> access.
> 
> 
> [ ... ]

Reviewed-by: Maxime Ripard <mripard@kernel.org>

Thanks!
Maxime

Re: [PATCH 00/10] drm/connector: add eld_mutex to protect connector->eld

[Dmitry Baryshkov]

On Mon, Dec 02, 2024 at 10:19:41AM +0000, Maxime Ripard wrote:
> On Sun, 1 Dec 2024 01:55:17 +0200, Dmitry Baryshkov wrote:
> > The connector->eld is accessed by the .get_eld() callback. This access
> > can collide with the drm_edid_to_eld() updating the data at the same
> > time. Add drm_connector.eld_mutex to protect the data from concurrenct
> > access.
> > 
> > 
> > [ ... ]
> 
> Reviewed-by: Maxime Ripard <mripard@kernel.org>

Thanks!

I'm going to post v2 to fix Jani's comment, but what should be the merge
strategy? Merge patches 1-3, 5, 9-10 through drm-misc and the rest (AMD,
i915, MSM, radeon) through the driver trees?

-- 
With best wishes
Dmitry

Re: [PATCH 00/10] drm/connector: add eld_mutex to protect connector->eld

[Maxime Ripard]

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On Mon, Dec 02, 2024 at 01:03:07PM +0200, Dmitry Baryshkov wrote:
> On Mon, Dec 02, 2024 at 10:19:41AM +0000, Maxime Ripard wrote:
> > On Sun, 1 Dec 2024 01:55:17 +0200, Dmitry Baryshkov wrote:
> > > The connector->eld is accessed by the .get_eld() callback. This access
> > > can collide with the drm_edid_to_eld() updating the data at the same
> > > time. Add drm_connector.eld_mutex to protect the data from concurrenct
> > > access.
> > > 
> > > 
> > > [ ... ]
> > 
> > Reviewed-by: Maxime Ripard <mripard@kernel.org>
> 
> Thanks!
> 
> I'm going to post v2 to fix Jani's comment, but what should be the merge
> strategy? Merge patches 1-3, 5, 9-10 through drm-misc and the rest (AMD,
> i915, MSM, radeon) through the driver trees?

The easiest is probably to merge everything through drm-misc if everyone agrees.

Maxime

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