drm/i915/adl_p: Disable FIFO underrun recovery
The FIFO underrun recovery mechanism has a boatload of cases
where it can't be used. The description is also a bit ambiguous
as it doesn't specify whether plane downscaling needs to be considered
or just pipe downscaling. We may not even have sufficient state
tracking to decide this on demand, so for now just disable the
whole thing.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210526173600.27708-1-ville.syrjala@linux.intel.com
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 5fbe5c7..dd522e4 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -8362,6 +8362,7 @@ enum {
#define _PIPEC_CHICKEN 0x72038
#define PIPE_CHICKEN(pipe) _MMIO_PIPE(pipe, _PIPEA_CHICKEN,\
_PIPEB_CHICKEN)
+#define UNDERRUN_RECOVERY_DISABLE REG_BIT(30)
#define PIXEL_ROUNDING_TRUNC_FB_PASSTHRU (1 << 15)
#define PER_PIXEL_ALPHA_BYPASS_EN (1 << 7)