Add a workaround to fix BS-BS jitter issues on MST links, aligning DPT/DPTP MTPs.
Bspec: 50050, 55424 Signed-off-by: Imre Deak <[email protected]> --- drivers/gpu/drm/i915/display/intel_dp_mst.c | 3 +++ drivers/gpu/drm/i915/i915_reg.h | 1 + 2 files changed, 4 insertions(+) diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c index 23f3f7fab9d0b..26c838ac9e411 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c @@ -1128,6 +1128,9 @@ static void enable_bs_jitter_was(const struct intel_crtc_state *crtc_state) set |= DP_MST_SHORT_HBLANK_WA(crtc_state->cpu_transcoder); else if (crtc_state->fec_enable) clear |= DP_MST_SHORT_HBLANK_WA(crtc_state->cpu_transcoder); + + if (crtc_state->fec_enable || intel_dp_is_uhbr(crtc_state)) + set |= DP_MST_DPT_DPTP_ALIGN_WA(crtc_state->cpu_transcoder); } if (!clear && !set) diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h index 091edc1071e0e..eecbdecb8ed40 100644 --- a/drivers/gpu/drm/i915/i915_reg.h +++ b/drivers/gpu/drm/i915/i915_reg.h @@ -4556,6 +4556,7 @@ #define GLK_CL0_PWR_DOWN REG_BIT(10) #define CHICKEN_MISC_3 _MMIO(0x42088) +#define DP_MST_DPT_DPTP_ALIGN_WA(trans) REG_BIT(9 + (trans) - TRANSCODER_A) #define DP_MST_SHORT_HBLANK_WA(trans) REG_BIT(5 + (trans) - TRANSCODER_A) #define DP_MST_FEC_BS_JITTER_WA(trans) REG_BIT(0 + (trans) - TRANSCODER_A) -- 2.39.2
