From: Peichen Huang peichen.huang@amd.com

[Why] DPIA doesn't support UHBR, driver should not enable UHBR for dp tunneling

[How] limit DPIA link rate to HBR3

Cc: Mario Limonciello mario.limonciello@amd.com Cc: Alex Deucher alexander.deucher@amd.com Cc: stable@vger.kernel.org Acked-by: Stylon Wang stylon.wang@amd.com Signed-off-by: Peichen Huang peichen.huang@amd.com Reviewed-by: Mustapha Ghaddar Mustapha.Ghaddar@amd.com --- drivers/gpu/drm/amd/display/dc/link/link_detection.c | 5 +++++ 1 file changed, 5 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/dc/link/link_detection.c b/drivers/gpu/drm/amd/display/dc/link/link_detection.c index 17904de4f155..8041b8369e45 100644 --- a/drivers/gpu/drm/amd/display/dc/link/link_detection.c +++ b/drivers/gpu/drm/amd/display/dc/link/link_detection.c @@ -984,6 +984,11 @@ static bool detect_link_and_local_sink(struct dc_link *link, (link->dpcd_caps.dongle_type != DISPLAY_DONGLE_DP_HDMI_CONVERTER)) converter_disable_audio = true; + + /* limited link rate to HBR3 for DPIA until we implement USB4 V2 */ + if (link->ep_type == DISPLAY_ENDPOINT_USB4_DPIA && + link->reported_link_cap.link_rate > LINK_RATE_HIGH3) + link->reported_link_cap.link_rate = LINK_RATE_HIGH3; break; }