drm/i915/adlp: Add MST short HBlank WA (Wa_14014143976)
Add a workaround to fix BS jitter issues on MST links if the HBLANK
period is less than 1 MTP. The WA applies only to UHBR rates while on
non-UHBR the specification requires disabling it explicitly - presumedly
because the register's reset value has the WA enabled.
Bspec: 50050, 55424
Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240129175533.904590-3-imre.deak@intel.com
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 1e8720e..81eb36f 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -4565,6 +4565,7 @@
#define GLK_CL0_PWR_DOWN REG_BIT(10)
#define CHICKEN_MISC_3 _MMIO(0x42088)
+#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)
#define CHICKEN_MISC_4 _MMIO(0x4208c)
