[PATCH] drm/amd/display: Add dm support for DP 1.4 Compliance edid corruption test

[Harry Wentland]

On 2020-04-29 1:58 p.m., Jerry (Fangzhi) Zuo wrote:
> It works together with drm framework
> "drm: Add support for DP 1.4 Compliance edid corruption test"
> 
> Signed-off-by: Jerry (Fangzhi) Zuo <Jerry.Zuo at amd.com>
> ---
>  .../amd/display/amdgpu_dm/amdgpu_dm_helpers.c | 40 ++++++-------------
>  1 file changed, 13 insertions(+), 27 deletions(-)
> 
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
> index c407f06cd1f5..b086d5c906e0 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
> @@ -554,6 +554,7 @@ enum dc_edid_status dm_helpers_read_local_edid(
>  		struct dc_sink *sink)
>  {
>  	struct amdgpu_dm_connector *aconnector = link->priv;
> +	struct drm_connector *connector = &aconnector->base;
>  	struct i2c_adapter *ddc;
>  	int retry = 3;
>  	enum dc_edid_status edid_status;
> @@ -571,6 +572,15 @@ enum dc_edid_status dm_helpers_read_local_edid(
>  
>  		edid = drm_get_edid(&aconnector->base, ddc);
>  
> +		/* DP Compliance Test 4.2.2.6 */
> +		if (link->aux_mode && connector->edid_corrupt)
> +			drm_dp_send_real_edid_checksum(&aconnector->dm_dp_aux.aux, connector->real_edid_checksum);
> +
> +		if (!edid && connector->edid_corrupt) {
> +			connector->edid_corrupt = false;
> +			return EDID_BAD_CHECKSUM;

You return EDID_BAD_CHECKSUM here but the surrounding loop uses
"edid_status == EDID_BAD_CHECKSUM" as condition to go again. Is this
duplicating functionality that dm_helpers_parse_edid_caps did?

Harry

> +		}
> +
>  		if (!edid)
>  			return EDID_NO_RESPONSE;
>  
> @@ -605,34 +615,10 @@ enum dc_edid_status dm_helpers_read_local_edid(
>  		DRM_ERROR("EDID err: %d, on connector: %s",
>  				edid_status,
>  				aconnector->base.name);
> -	if (link->aux_mode) {
> -		union test_request test_request = { {0} };
> -		union test_response test_response = { {0} };
> -
> -		dm_helpers_dp_read_dpcd(ctx,
> -					link,
> -					DP_TEST_REQUEST,
> -					&test_request.raw,
> -					sizeof(union test_request));
> -
> -		if (!test_request.bits.EDID_READ)
> -			return edid_status;
>  
> -		test_response.bits.EDID_CHECKSUM_WRITE = 1;
> -
> -		dm_helpers_dp_write_dpcd(ctx,
> -					link,
> -					DP_TEST_EDID_CHECKSUM,
> -					&sink->dc_edid.raw_edid[sink->dc_edid.length-1],
> -					1);
> -
> -		dm_helpers_dp_write_dpcd(ctx,
> -					link,
> -					DP_TEST_RESPONSE,
> -					&test_response.raw,
> -					sizeof(test_response));
> -
> -	}
> +	/* DP Compliance Test 4.2.2.3 */
> +	if (link->aux_mode)
> +		drm_dp_send_real_edid_checksum(&aconnector->dm_dp_aux.aux, sink->dc_edid.raw_edid[sink->dc_edid.length-1]);
>  
>  	return edid_status;
>  }
>