This patch adds an essential check related to the size of the
payload to be transferred via aux channel.
Without this check dal_ddc_service_read_dpcd_data() is fed with
inappropriate payload size leading to deadlocks.
Signed-off-by: Shirish S <shirish.s at amd.com>
---
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
index 39cfe0f..8291d74 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
@@ -85,6 +85,9 @@ static ssize_t dm_dp_aux_transfer(struct drm_dp_aux *aux,
enum ddc_result res;
ssize_t read_bytes;
+ if (WARN_ON(msg->size > 16))
+ return -E2BIG;
+
switch (msg->request & ~DP_AUX_I2C_MOT) {
case DP_AUX_NATIVE_READ:
read_bytes = dal_ddc_service_read_dpcd_data(
--
2.7.4
