-----Original Message----- From: Nikula, Jani jani.nikula@intel.com Sent: Tuesday, September 24, 2024 9:00 PM To: intel-gfx@lists.freedesktop.org; intel-xe@lists.freedesktop.org Cc: Nikula, Jani jani.nikula@intel.com; Sean Paul seanpaul@chromium.org; Kandpal, Suraj suraj.kandpal@intel.com; Ville Syrjälä ville.syrjala@linux.intel.com; stable@vger.kernel.org Subject: [PATCH] drm/i915/hdcp: fix connector refcounting
We acquire a connector reference before scheduling an HDCP prop work, and expect the work function to release the reference.
However, if the work was already queued, it won't be queued multiple times, and the reference is not dropped.
Release the reference immediately if the work was already queued.
LGTM, Reviewed-by: Suraj Kandpal suraj.kandpal@intel.com
Fixes: a6597faa2d59 ("drm/i915: Protect workers against disappearing connectors") Cc: Sean Paul seanpaul@chromium.org Cc: Suraj Kandpal suraj.kandpal@intel.com Cc: Ville Syrjälä ville.syrjala@linux.intel.com Cc: stable@vger.kernel.org # v5.10+ Signed-off-by: Jani Nikula jani.nikula@intel.com
I don't know that we have any bugs open about this. Or how it would manifest itself. Memory leak on driver unload? I just spotted this while reading the code for other reasons.
drivers/gpu/drm/i915/display/intel_hdcp.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_hdcp.c b/drivers/gpu/drm/i915/display/intel_hdcp.c index 2afa92321b08..cad309602617 100644 --- a/drivers/gpu/drm/i915/display/intel_hdcp.c +++ b/drivers/gpu/drm/i915/display/intel_hdcp.c @@ -1097,7 +1097,8 @@ static void intel_hdcp_update_value(struct intel_connector *connector, hdcp->value = value; if (update_property) { drm_connector_get(&connector->base);
queue_work(i915->unordered_wq, &hdcp->prop_work);
if (!queue_work(i915->unordered_wq, &hdcp->prop_work))drm_connector_put(&connector->base);}
@@ -2531,7 +2532,8 @@ void intel_hdcp_update_pipe(struct intel_atomic_state *state, mutex_lock(&hdcp->mutex); hdcp->value = DRM_MODE_CONTENT_PROTECTION_DESIRED; drm_connector_get(&connector->base);
queue_work(i915->unordered_wq, &hdcp->prop_work);
if (!queue_work(i915->unordered_wq, &hdcp->prop_work))drm_connector_put(&connector->base);@@ -2548,7 +2550,9 @@ void intel_hdcp_update_pipe(struct intel_atomic_state *state, */ if (!desired_and_not_enabled && !content_protection_type_changed) { drm_connector_get(&connector->base);
queue_work(i915->unordered_wq, &hdcp-prop_work);
if (!queue_work(i915->unordered_wq, &hdcp-prop_work))
drm_connector_put(&connector->base);- } }
-- 2.39.2