Commit 2a7b5829 authored Mar 13, 2018 by Shirish S Committed by Alex Deucher Mar 14, 2018

drm/amd/display: Check msg->size before starting aux transfer



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@amd.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

parent 17ac5036

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -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(