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 Tested-by: Daniel Wheeler daniel.wheeler@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com (cherry picked from commit 0e69ef6ea82e8eece7d2b2b45a0da9670eaaefff) This was CC to stable, but failed to apply because the file was renamed in 6.3-rc1 as part of 54618888d1ea ("drm/amd/display: break down dc_link.c") Signed-off-by: Mario Limonciello mario.limonciello@amd.com --- drivers/gpu/drm/amd/display/dc/core/dc_link.c | 5 +++++ 1 file changed, 5 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link.c b/drivers/gpu/drm/amd/display/dc/core/dc_link.c index 5d53e54ebe90..63daf6ecbda7 100644 --- a/drivers/gpu/drm/amd/display/dc/core/dc_link.c +++ b/drivers/gpu/drm/amd/display/dc/core/dc_link.c @@ -1141,6 +1141,11 @@ 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; }