From 7f6e7186f9f44918972874608022975912f03e00 Mon Sep 17 00:00:00 2001 From: Nikola Cornij Date: Thu, 1 Aug 2019 15:52:58 -0400 Subject: [PATCH] drm/amd/display: Zero-out dsc init regs [why] Before a statically allocated PPS data structure, that did get zeroed-out at startup, had been re-used for making packed PPS SDP. With S3 fix, using a non-initialized PPS data structure was introduced, while wrongly assuming it'd get initialized before it's populated. As a consequence 'vbr_enable' and perhaps some other fields are left uninitialized when making packed PPS SDP. This can affect 'simple_422' as well because of the way PPS SDP packing is done (the fields are not masked first, only shifted). The behavior will be different, depending on the content of uninitialized data. [how] Zero-out PPS data structure at initialization time before it's populated Fixes: 1a9e3d4569fc ("drm/amd/display: Set DSC before DIG front-end is connected to its back-end") Signed-off-by: Nikola Cornij Reviewed-by: Wenjing Liu Acked-by: Bhawanpreet Lakha Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/display/dc/dcn20/dcn20_dsc.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_dsc.c b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_dsc.c index 379c9e4ac63be..c4f861e6bd537 100644 --- a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_dsc.c +++ b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_dsc.c @@ -447,6 +447,8 @@ static void dsc_init_reg_values(struct dsc_reg_values *reg_vals) { int i; + memset(reg_vals, 0, sizeof(struct dsc_reg_values)); + /* Non-PPS values */ reg_vals->dsc_clock_enable = 1; reg_vals->dsc_clock_gating_disable = 0; -- 2.30.2