From 2a5dd86a69ea5435f1a837bdb7fafcda609a7c91 Mon Sep 17 00:00:00 2001 From: Taimur Hassan Date: Fri, 11 Nov 2022 14:11:00 -0500 Subject: drm/amd/display: Avoid setting pixel rate divider to N/A [Why] Pixel rate divider values should never be set to N/A (0xF) as the K1/K2 field is only 1/2 bits wide. [How] Set valid divider values for virtual and FRL/DP2 cases. Reviewed-by: Nicholas Kazlauskas Acked-by: Brian Chang Signed-off-by: Taimur Hassan Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/display/dc/dcn314/dcn314_dccg.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'drivers/gpu/drm/amd/display/dc/dcn314/dcn314_dccg.c') diff --git a/drivers/gpu/drm/amd/display/dc/dcn314/dcn314_dccg.c b/drivers/gpu/drm/amd/display/dc/dcn314/dcn314_dccg.c index 1bd7e0f327d8..389a8938ee45 100644 --- a/drivers/gpu/drm/amd/display/dc/dcn314/dcn314_dccg.c +++ b/drivers/gpu/drm/amd/display/dc/dcn314/dcn314_dccg.c @@ -96,6 +96,13 @@ static void dccg314_set_pixel_rate_div( struct dcn_dccg *dccg_dcn = TO_DCN_DCCG(dccg); enum pixel_rate_div cur_k1 = PIXEL_RATE_DIV_NA, cur_k2 = PIXEL_RATE_DIV_NA; + // Don't program 0xF into the register field. Not valid since + // K1 / K2 field is only 1 / 2 bits wide + if (k1 == PIXEL_RATE_DIV_NA || k2 == PIXEL_RATE_DIV_NA) { + BREAK_TO_DEBUGGER(); + return; + } + dccg314_get_pixel_rate_div(dccg, otg_inst, &cur_k1, &cur_k2); if (k1 == PIXEL_RATE_DIV_NA || k2 == PIXEL_RATE_DIV_NA || (k1 == cur_k1 && k2 == cur_k2)) return; -- cgit v1.2.3