From: Wenjing Liu Date: Fri, 29 Apr 2022 19:42:30 +0000 (-0400) Subject: drm/amd/display: do not calculate DP2.0 SST payload when link is off X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=c371b0d12d0b8497355cc1ac2a11accd2f5b8528;p=linux.git drm/amd/display: do not calculate DP2.0 SST payload when link is off [Why & How] There is a chance where the RX issues HPD deassert in the middle of link training, this will cause our logic to abort link training and turn off link. However our payload allocation logic needs to use current link settings to determine average time slot per MTP. This will need to use current link bandwidth as divider. This causes divide by zero error occasionally. The fix is to skip DP2.0 payload allocation logic if current link is not in 128b/132b mode. Reviewed-by: George Shen Acked-by: Stylon Wang Signed-off-by: Wenjing Liu Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher --- 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 48e274f9ea848..07f154fc4e567 100644 --- a/drivers/gpu/drm/amd/display/dc/core/dc_link.c +++ b/drivers/gpu/drm/amd/display/dc/core/dc_link.c @@ -3546,7 +3546,8 @@ static enum dc_status dc_link_update_sst_payload(struct pipe_ctx *pipe_ctx, } /* slot X.Y for SST payload allocate */ - if (allocate) { + if (allocate && dp_get_link_encoding_format(&link->cur_link_settings) == + DP_128b_132b_ENCODING) { avg_time_slots_per_mtp = calculate_sst_avg_time_slots_per_mtp(stream, link); dc_log_vcp_x_y(link, avg_time_slots_per_mtp);