From ce740545c0c9a144e489a85363d13a9c03dd08e9 Mon Sep 17 00:00:00 2001 From: George Shen Date: Thu, 16 Sep 2021 19:55:39 -0400 Subject: [PATCH] drm/amd/display: Handle Y carry-over in VCP X.Y calculation commit 719564737a9ac3d0b49c314450b56cf6f7d71358 upstream. Theoretically rare corner case where ceil(Y) results in rounding up to an integer. If this happens, the 1 should be carried over to the X value. CC: stable@vger.kernel.org Reviewed-by: Rodrigo Siqueira Signed-off-by: George Shen Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher Signed-off-by: Greg Kroah-Hartman --- .../drm/amd/display/dc/dcn31/dcn31_hpo_dp_link_encoder.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/gpu/drm/amd/display/dc/dcn31/dcn31_hpo_dp_link_encoder.c b/drivers/gpu/drm/amd/display/dc/dcn31/dcn31_hpo_dp_link_encoder.c index 80dfaa4d4d81..eb3a4624f781 100644 --- a/drivers/gpu/drm/amd/display/dc/dcn31/dcn31_hpo_dp_link_encoder.c +++ b/drivers/gpu/drm/amd/display/dc/dcn31/dcn31_hpo_dp_link_encoder.c @@ -393,6 +393,12 @@ void dcn31_hpo_dp_link_enc_set_throttled_vcp_size( x), 25)); + // If y rounds up to integer, carry it over to x. + if (y >> 25) { + x += 1; + y = 0; + } + switch (stream_encoder_inst) { case 0: REG_SET_2(DP_DPHY_SYM32_VC_RATE_CNTL0, 0,