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authorDmitry Baryshkov <dmitry.baryshkov@linaro.org>2024-12-06 11:43:04 +0200
committerDmitry Baryshkov <dmitry.baryshkov@linaro.org>2024-12-16 18:02:07 +0200
commitdf7c8e3dde37a9d81c0613285b43600f3cc70f34 (patch)
treee63d1ec341d80bd6f76a492525b10dae68e5c747 /drivers/gpu/drm/drm_edid.c
parentdrm: zynqmp_dp: Fix integer overflow in zynqmp_dp_rate_get() (diff)
downloadlinux-df7c8e3dde37a9d81c0613285b43600f3cc70f34.tar.gz
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drm/connector: add mutex to protect ELD from concurrent access
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. Reviewed-by: Maxime Ripard <mripard@kernel.org> Link: https://patchwork.freedesktop.org/patch/msgid/20241206-drm-connector-eld-mutex-v2-1-c9bce1ee8bea@linaro.org Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Diffstat (limited to 'drivers/gpu/drm/drm_edid.c')
-rw-r--r--drivers/gpu/drm/drm_edid.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 855beafb76ff..13bc4c290b17 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -5605,7 +5605,9 @@ EXPORT_SYMBOL(drm_edid_get_monitor_name);
static void clear_eld(struct drm_connector *connector)
{
+ mutex_lock(&connector->eld_mutex);
memset(connector->eld, 0, sizeof(connector->eld));
+ mutex_unlock(&connector->eld_mutex);
connector->latency_present[0] = false;
connector->latency_present[1] = false;
@@ -5657,6 +5659,8 @@ 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 +5721,8 @@ 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,