diff options
| author | Ville Syrjälä <ville.syrjala@linux.intel.com> | 2019-02-04 22:22:32 +0200 |
|---|---|---|
| committer | Ville Syrjälä <ville.syrjala@linux.intel.com> | 2019-02-05 21:58:11 +0200 |
| commit | bf002c100740f4ae01d0d86b44f65a712ee14031 (patch) | |
| tree | 2e6269e9475ea32c8f2901accaa7cca1286b01e0 | |
| parent | 108d14bdaef67617412af3f40256810281464425 (diff) | |
drm/i915: W/A for underruns with WM1+ disabled on icl
Disabling WM1+ on ICL causes tons of underruns with
linear/X-tiled framebuffers. We can avoid this by flipping
on a chicken bit affecting the way the hw fill the FIFO.
This may not be the final solution but should hopefully
avoid some underruns in the meantime.
v2: Apparently PIPE_CHICKEN is icl+ only
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190204202232.27153-1-ville.syrjala@linux.intel.com
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
| -rw-r--r-- | drivers/gpu/drm/i915/i915_reg.h | 1 | ||||
| -rw-r--r-- | drivers/gpu/drm/i915/intel_display.c | 6 |
2 files changed, 7 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h index ede54fdc1676..12964b0fbc54 100644 --- a/drivers/gpu/drm/i915/i915_reg.h +++ b/drivers/gpu/drm/i915/i915_reg.h @@ -7618,6 +7618,7 @@ enum { #define _PIPEB_CHICKEN 0x71038 #define _PIPEC_CHICKEN 0x72038 #define PER_PIXEL_ALPHA_BYPASS_EN (1 << 7) +#define PM_FILL_MAINTAIN_DBUF_FULLNESS (1 << 0) #define PIPE_CHICKEN(pipe) _MMIO_PIPE(pipe, _PIPEA_CHICKEN,\ _PIPEB_CHICKEN) diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index dc7a2aa62874..9db931a450f6 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -3911,6 +3911,12 @@ static void icl_set_pipe_chicken(struct intel_crtc *crtc) */ tmp |= PER_PIXEL_ALPHA_BYPASS_EN; + /* + * W/A for underruns with linear/X-tiled with + * WM1+ disabled. + */ + tmp |= PM_FILL_MAINTAIN_DBUF_FULLNESS; + I915_WRITE(PIPE_CHICKEN(pipe), tmp); } |