From e0f7ff99c92ff5e033e169c30cff607ff7c17192 Mon Sep 17 00:00:00 2001 From: Jaehyun Chung Date: Wed, 5 Aug 2020 17:28:53 -0400 Subject: [PATCH] drm/amd/display: Mask DPCD field to avoid reading unsupported field value [Why] DSC will be disabled if DPCD 0006F[6:3] is set to a non-zero value because bits 6:3 are not currently supported. When 6:3 is populated, an unsupported INCREMENT OF bits_per_pixel value is read (DPCD 0006F[2:0]) [How] Mask the INCREMENT OF bits_per_pixel field so that values in the unsupported field are ignored. Signed-off-by: Jaehyun Chung Reviewed-by: Wenjing Liu Acked-by: Rodrigo Siqueira Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/display/dc/dsc/dc_dsc.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/amd/display/dc/dsc/dc_dsc.c b/drivers/gpu/drm/amd/display/dc/dsc/dc_dsc.c index da1b654833d5..4c844cfaa956 100644 --- a/drivers/gpu/drm/amd/display/dc/dsc/dc_dsc.c +++ b/drivers/gpu/drm/amd/display/dc/dsc/dc_dsc.c @@ -192,8 +192,10 @@ static bool dsc_throughput_from_dpcd(int dpcd_throughput, int *throughput) } -static bool dsc_bpp_increment_div_from_dpcd(int bpp_increment_dpcd, uint32_t *bpp_increment_div) +static bool dsc_bpp_increment_div_from_dpcd(uint8_t bpp_increment_dpcd, uint32_t *bpp_increment_div) { + // Mask bpp increment dpcd field to avoid reading other fields + bpp_increment_dpcd &= 0x7; switch (bpp_increment_dpcd) { case 0: -- GitLab