if (false == dc_link_construct(link, init_params))
goto construct_fail;
+ /*
+ * Must use preferred_link_setting, not reported_link_cap or verified_link_cap,
+ * since struct preferred_link_setting won't be reset after S3.
+ */
+ link->preferred_link_setting.dpcd_source_device_specific_field_support = true;
+
return link;
construct_fail:
uint8_t hblank_size = (uint8_t)link->dc->caps.min_horizontal_blanking_period;
- result_write_min_hblank = core_link_write_dpcd(link,
- DP_SOURCE_MINIMUM_HBLANK_SUPPORTED, (uint8_t *)(&hblank_size),
- sizeof(hblank_size));
+ if (link->preferred_link_setting.dpcd_source_device_specific_field_support) {
+ result_write_min_hblank = core_link_write_dpcd(link,
+ DP_SOURCE_MINIMUM_HBLANK_SUPPORTED, (uint8_t *)(&hblank_size),
+ sizeof(hblank_size));
+
+ if (result_write_min_hblank == DC_ERROR_UNEXPECTED)
+ link->preferred_link_setting.dpcd_source_device_specific_field_support = false;
+ } else {
+ DC_LOG_DC("Sink device does not support 00340h DPCD write. Skipping on purpose.\n");
+ }
}
+
DC_TRACE_LEVEL_MESSAGE(DAL_TRACE_LEVEL_INFORMATION,
WPP_BIT_FLAG_DC_DETECTION_DP_CAPS,
"result=%u link_index=%u enum dce_version=%d DPCD=0x%04X min_hblank=%u branch_dev_id=0x%x branch_dev_name='%c%c%c%c%c%c'",