From: Anthony Koo <Anthony.Koo@xxxxxxx> [Why] AUX transaction returns success, but data has invalid lane count and rate which when passed to VBIOS command table causes it to soft hang [How] Do some sanity checking and fail if the DPCD caps are invalid. Change-Id: I846615c12223f75d100067ce76792f19b64beab3 Signed-off-by: Anthony Koo <Anthony.Koo@xxxxxxx> Reviewed-by: Tony Cheng <Tony.Cheng@xxxxxxx> Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@xxxxxxx> --- drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c | 9 +++++++++ 1 file changed, 9 insertions(+) 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 8ad79df56bf8..e1081e2dffdc 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 @@ -2474,6 +2474,15 @@ static bool retrieve_link_cap(struct dc_link *link) } } + /* Error condition checking... + * It is impossible for Sink to report Max Lane Count = 0. + * It is possible for Sink to report Max Link Rate = 0, if it is + * an eDP device that is reporting specialized link rates in the + * SUPPORTED_LINK_RATE table. + */ + if (dpcd_data[DP_MAX_LANE_COUNT - DP_DPCD_REV] == 0) + return false; + link->dpcd_caps.dpcd_rev.raw = dpcd_data[DP_DPCD_REV - DP_DPCD_REV]; -- 2.17.1 _______________________________________________ amd-gfx mailing list amd-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/amd-gfx
