From 80c6d6804f31451848a3956a70c2bcb1f07cfcb0 Mon Sep 17 00:00:00 2001 From: Aurabindo Pillai Date: Wed, 15 Feb 2023 12:51:20 -0500 Subject: [PATCH] drm/amd/display: disable SubVP + DRR to prevent underflow [Why&How] Temporarily disable SubVP+DRR since Xorg has an architectural limitation where freesync will not work in a multi monitor configuration. SubVP+DRR requires that freesync be working. Whether OS has variable refresh setting enabled or not, the state on the crtc remains same unless an application requests VRR. Due to this, there is no way to know whether freesync will actually work or not while we are on the desktop from the kernel's perspective. If userspace does not have a limitation with multi-display freesync (for example wayland), then this feature can be enabled by adding a dcfeaturemask option to amdgpu on the kernel cmdline like: amdgpu.dcfeaturemask=0x200 Signed-off-by: Aurabindo Pillai Reviewed-by: Rodrigo Siqueira Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 5 +++++ drivers/gpu/drm/amd/display/dc/dc.h | 2 +- drivers/gpu/drm/amd/display/dc/dml/dcn32/dcn32_fpu.c | 4 ++++ drivers/gpu/drm/amd/include/amd_shared.h | 1 + 4 files changed, 11 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c index 5a2e09e97dd5..c420bce47acb 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -1604,6 +1604,11 @@ static int amdgpu_dm_init(struct amdgpu_device *adev) if (amdgpu_dc_feature_mask & DC_DISABLE_LTTPR_DP2_0) init_data.flags.allow_lttpr_non_transparent_mode.bits.DP2_0 = true; + /* Disable SubVP + DRR config by default */ + init_data.flags.disable_subvp_drr = true; + if (amdgpu_dc_feature_mask & DC_ENABLE_SUBVP_DRR) + init_data.flags.disable_subvp_drr = false; + init_data.flags.seamless_boot_edp_requested = false; if (check_seamless_boot_capability(adev)) { diff --git a/drivers/gpu/drm/amd/display/dc/dc.h b/drivers/gpu/drm/amd/display/dc/dc.h index 2bf0a467d45f..1fde43378689 100644 --- a/drivers/gpu/drm/amd/display/dc/dc.h +++ b/drivers/gpu/drm/amd/display/dc/dc.h @@ -409,7 +409,7 @@ struct dc_config { bool force_bios_enable_lttpr; uint8_t force_bios_fixed_vs; int sdpif_request_limit_words_per_umc; - + bool disable_subvp_drr; }; enum visual_confirm { diff --git a/drivers/gpu/drm/amd/display/dc/dml/dcn32/dcn32_fpu.c b/drivers/gpu/drm/amd/display/dc/dml/dcn32/dcn32_fpu.c index 3372ede2dc28..e47828e3b6d5 100644 --- a/drivers/gpu/drm/amd/display/dc/dml/dcn32/dcn32_fpu.c +++ b/drivers/gpu/drm/amd/display/dc/dml/dcn32/dcn32_fpu.c @@ -880,6 +880,10 @@ static bool subvp_drr_schedulable(struct dc *dc, struct dc_state *context, struc int16_t stretched_drr_us = 0; int16_t drr_stretched_vblank_us = 0; int16_t max_vblank_mallregion = 0; + const struct dc_config *config = &dc->config; + + if (config->disable_subvp_drr) + return false; // Find SubVP pipe for (i = 0; i < dc->res_pool->pipe_count; i++) { diff --git a/drivers/gpu/drm/amd/include/amd_shared.h b/drivers/gpu/drm/amd/include/amd_shared.h index f175e65b853a..e4a22c68517d 100644 --- a/drivers/gpu/drm/amd/include/amd_shared.h +++ b/drivers/gpu/drm/amd/include/amd_shared.h @@ -240,6 +240,7 @@ enum DC_FEATURE_MASK { DC_DISABLE_LTTPR_DP2_0 = (1 << 6), //0x40, disabled by default DC_PSR_ALLOW_SMU_OPT = (1 << 7), //0x80, disabled by default DC_PSR_ALLOW_MULTI_DISP_OPT = (1 << 8), //0x100, disabled by default + DC_ENABLE_SUBVP_DRR = (1 << 9), // 0x200, disabled by default }; enum DC_DEBUG_MASK { -- 2.39.5