[PATCH 5.14 019/151] drm/i915: Extend the async flip VT-d w/a to skl/bxt

Greg Kroah-Hartman
2021-10-11T13:59:55Z

From: Ville Syrjälä <ville.syrjala@linux.intel.com>

commit b2d73debfdc16b742e64948dc4461876af3f8c10 upstream.

Looks like skl/bxt/derivatives also need the plane stride
stretch w/a when using async flips and VT-d is enabled, or
else we get corruption on screen. To my surprise this was
even documented in bspec, but only as a note on the
CHICHKEN_PIPESL register description rather than on the
w/a list.

So very much the same thing as on HSW/BDW, except the bits
moved yet again.

Cc: stable@vger.kernel.org
Cc: Karthik B S <karthik.b.s@intel.com>
Fixes: 55ea1cb178ef ("drm/i915: Enable async flips in i915")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210930190943.17547-1-ville.syrjala@linux.intel.com
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
(cherry picked from commit d08df3b0bdb25546e86dc9a6c4e3ec0c43832299)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/gpu/drm/i915/i915_reg.h | 5 +++++
drivers/gpu/drm/i915/intel_pm.c | 12 ++++++++++++
2 files changed, 17 insertions(+)

--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -8150,6 +8150,11 @@ enum {
#define HSW_SPR_STRETCH_MAX_X1 REG_FIELD_PREP(HSW_SPR_STRETCH_MAX_MASK, 3)
#define HSW_FBCQ_DIS (1 << 22)
#define BDW_DPRS_MASK_VBLANK_SRD (1 << 0)
+#define SKL_PLANE1_STRETCH_MAX_MASK REG_GENMASK(1, 0)
+#define SKL_PLANE1_STRETCH_MAX_X8 REG_FIELD_PREP(SKL_PLANE1_STRETCH_MAX_MASK, 0)
+#define SKL_PLANE1_STRETCH_MAX_X4 REG_FIELD_PREP(SKL_PLANE1_STRETCH_MAX_MASK, 1)
+#define SKL_PLANE1_STRETCH_MAX_X2 REG_FIELD_PREP(SKL_PLANE1_STRETCH_MAX_MASK, 2)
+#define SKL_PLANE1_STRETCH_MAX_X1 REG_FIELD_PREP(SKL_PLANE1_STRETCH_MAX_MASK, 3)
#define CHICKEN_PIPESL_1(pipe) _MMIO_PIPE(pipe, _CHICKEN_PIPESL_1_A, _CHICKEN_PIPESL_1_B)

#define _CHICKEN_TRANS_A 0x420c0
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -76,6 +76,8 @@ struct intel_wm_config {

static void gen9_init_clock_gating(struct drm_i915_private *dev_priv)
{
+ enum pipe pipe;
+
if (HAS_LLC(dev_priv)) {
/*
* WaCompressedResourceDisplayNewHashMode:skl,kbl
@@ -89,6 +91,16 @@ static void gen9_init_clock_gating(struc
SKL_DE_COMPRESSED_HASH_MODE);
}

+ for_each_pipe(dev_priv, pipe) {
+ /*
+ * "Plane N strech max must be programmed to 11b (x1)
+ * when Async flips are enabled on that plane."
+ */
+ if (!IS_GEMINILAKE(dev_priv) && intel_vtd_active())
+ intel_uncore_rmw(&dev_priv->uncore, CHICKEN_PIPESL_1(pipe),
+ SKL_PLANE1_STRETCH_MAX_MASK, SKL_PLANE1_STRETCH_MAX_X1);
+ }
+
/* See Bspec note for PSR2_CTL bit 31, Wa#828:skl,bxt,kbl,cfl */
intel_uncore_write(&dev_priv->uncore, CHICKEN_PAR1_1,
intel_uncore_read(&dev_priv->uncore, CHICKEN_PAR1_1) | SKL_EDP_PSR_FIX_RDWRAP);