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@xxxxxxxxxx>
---
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
