[PATCH 3/6] drm/v3d: Don't bother flushing L1TD at job start.

From: Eric Anholt <eric@anholt.net>
To: dri-devel@lists.freedesktop.org
Cc: linux-kernel@vger.kernel.org,
	Dave Emett <david.emett@broadcom.com>,
	Thomas Spurden <thomas.spurden@broadcom.com>,
	Eric Anholt <eric@anholt.net>
Subject: [PATCH 3/6] drm/v3d: Don't bother flushing L1TD at job start.
Date: Fri, 30 Nov 2018 16:57:56 -0800	[thread overview]
Message-ID: <20181201005759.28093-3-eric@anholt.net> (raw)
In-Reply-To: <20181201005759.28093-1-eric@anholt.net>

This is the write combiner for TMU writes.  You're supposed to flush
that at job end if you had dirtied any cachelines.  Flushing it at job
start then doesn't make any sense.

Signed-off-by: Eric Anholt <eric@anholt.net>
Fixes: 57692c94dcbe ("drm/v3d: Introduce a new DRM driver for Broadcom V3D V3.x+")
---
 drivers/gpu/drm/v3d/v3d_gem.c | 12 ------------
 1 file changed, 12 deletions(-)

diff --git a/drivers/gpu/drm/v3d/v3d_gem.c b/drivers/gpu/drm/v3d/v3d_gem.c
index 34103205b7cb..cc4d025b01e0 100644
--- a/drivers/gpu/drm/v3d/v3d_gem.c
+++ b/drivers/gpu/drm/v3d/v3d_gem.c
@@ -139,22 +139,10 @@ v3d_invalidate_l2(struct v3d_dev *v3d, int core)
 		       V3D_L2CACTL_L2CENA);
 }
 
-static void
-v3d_invalidate_l1td(struct v3d_dev *v3d, int core)
-{
-	V3D_CORE_WRITE(core, V3D_CTL_L2TCACTL, V3D_L2TCACTL_TMUWCF);
-	if (wait_for(!(V3D_CORE_READ(core, V3D_CTL_L2TCACTL) &
-		       V3D_L2TCACTL_L2TFLS), 100)) {
-		DRM_ERROR("Timeout waiting for L1T write combiner flush\n");
-	}
-}
-
 /* Invalidates texture L2 cachelines */
 static void
 v3d_flush_l2t(struct v3d_dev *v3d, int core)
 {
-	v3d_invalidate_l1td(v3d, core);
-
 	V3D_CORE_WRITE(core, V3D_CTL_L2TCACTL,
 		       V3D_L2TCACTL_L2TFLS |
 		       V3D_SET_FIELD(V3D_L2TCACTL_FLM_FLUSH, V3D_L2TCACTL_FLM));
-- 
2.20.0.rc1

