From b3dcc6dc0f32612d04839c2fb32e94d0ebf92c98 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= <ville.syrjala@linux.intel.com>
Date: Fri, 4 Feb 2022 16:18:17 +0200
Subject: [PATCH] drm/i915: Populate pipe dbuf slices more accurately during
 readout
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Git-commit: 85bb289215cf37e05e9581b39b114db1293f9ecd
Patch-mainline: v5.17-rc4
References: bsc#1193640

During readout we cannot assume the planes are actually using the
slices they are supposed to use. The BIOS may have misprogrammed
things and put the planes onto the wrong dbuf slices. So let's
do the readout more carefully to make sure we really know which
dbuf slices are actually in use by the pipe at the time.

Cc: <stable@vger.kernel.org> # v5.14+
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220204141818.1900-2-ville.syrjala@linux.intel.com
Reviewed-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/gpu/drm/i915/intel_pm.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 2eb70ec38f6e..79d61a2935ea 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -6663,6 +6663,7 @@ void skl_wm_get_hw_state(struct drm_i915_private *dev_priv)
 		enum pipe pipe = crtc->pipe;
 		unsigned int mbus_offset;
 		enum plane_id plane_id;
+		u8 slices;
 
 		skl_pipe_wm_get_hw_state(crtc, &crtc_state->wm.skl.optimal);
 		crtc_state->wm.skl.raw = crtc_state->wm.skl.optimal;
@@ -6682,20 +6683,22 @@ void skl_wm_get_hw_state(struct drm_i915_private *dev_priv)
 			skl_ddb_entry_union(&dbuf_state->ddb[pipe], ddb_uv);
 		}
 
-		dbuf_state->slices[pipe] =
-			skl_compute_dbuf_slices(crtc, dbuf_state->active_pipes,
-						dbuf_state->joined_mbus);
-
 		dbuf_state->weight[pipe] = intel_crtc_ddb_weight(crtc_state);
 
 		/*
 		 * Used for checking overlaps, so we need absolute
 		 * offsets instead of MBUS relative offsets.
 		 */
-		mbus_offset = mbus_ddb_offset(dev_priv, dbuf_state->slices[pipe]);
+		slices = skl_compute_dbuf_slices(crtc, dbuf_state->active_pipes,
+						 dbuf_state->joined_mbus);
+		mbus_offset = mbus_ddb_offset(dev_priv, slices);
 		crtc_state->wm.skl.ddb.start = mbus_offset + dbuf_state->ddb[pipe].start;
 		crtc_state->wm.skl.ddb.end = mbus_offset + dbuf_state->ddb[pipe].end;
 
+		/* The slices actually used by the planes on the pipe */
+		dbuf_state->slices[pipe] =
+			skl_ddb_dbuf_slice_mask(dev_priv, &crtc_state->wm.skl.ddb);
+
 		drm_dbg_kms(&dev_priv->drm,
 			    "[CRTC:%d:%s] dbuf slices 0x%x, ddb (%d - %d), active pipes 0x%x, mbus joined: %s\n",
 			    crtc->base.base.id, crtc->base.name,
-- 
2.31.1