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authorAurabindo Pillai2020-04-07 10:22:27 -0400
committerAlex Deucher2020-04-24 09:41:31 -0400
commit933fe2cbf234afcd92d26e233c45f206af147616 (patch)
tree3a469ad55275e3072ceadcf5dbc0173e2c3c3b37
parente32b2484b3e00170b6cf57d99a18972e174e10ea (diff)
drm/amd/display: DispalyPort: Write OUI only if panel supports it
[why] Organizational Unit Identifier register is optional, and its presence is published via Down Stream Port Count register. Writing this register when not available will result in errors [how] Read this register and continue writing OUI only if the panel has the support advertised. Signed-off-by: Aurabindo Pillai <aurabindo.pillai@amd.com> Reviewed-by: Aric Cyr <Aric.Cyr@amd.com> Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
-rw-r--r--drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c15
1 files changed, 15 insertions, 0 deletions
diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
index 7cbb1efb4f68..aaa86f015ec0 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
@@ -4227,6 +4227,21 @@ void dp_set_fec_enable(struct dc_link *link, bool enable)
void dpcd_set_source_specific_data(struct dc_link *link)
{
const uint32_t post_oui_delay = 30; // 30ms
+ uint8_t dspc = 0;
+ enum dc_status ret = DC_ERROR_UNEXPECTED;
+
+ ret = core_link_read_dpcd(link, DP_DOWN_STREAM_PORT_COUNT, &dspc,
+ sizeof(dspc));
+
+ if (ret != DC_OK) {
+ DC_LOG_ERROR("Error in DP aux read transaction,"
+ " not writing source specific data\n");
+ return;
+ }
+
+ /* Return if OUI unsupported */
+ if (!(dspc & DP_OUI_SUPPORT))
+ return;
if (!link->dc->vendor_signature.is_valid) {
struct dpcd_amd_signature amd_signature;