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Diffstat (limited to 'target/linux/brcm2708/patches-4.4/0539-drm-vc4-Use-runtime-autosuspend-to-avoid-thrashing-V.patch')
-rw-r--r--target/linux/brcm2708/patches-4.4/0539-drm-vc4-Use-runtime-autosuspend-to-avoid-thrashing-V.patch78
1 files changed, 78 insertions, 0 deletions
diff --git a/target/linux/brcm2708/patches-4.4/0539-drm-vc4-Use-runtime-autosuspend-to-avoid-thrashing-V.patch b/target/linux/brcm2708/patches-4.4/0539-drm-vc4-Use-runtime-autosuspend-to-avoid-thrashing-V.patch
new file mode 100644
index 0000000000..ca9c2e8d4d
--- /dev/null
+++ b/target/linux/brcm2708/patches-4.4/0539-drm-vc4-Use-runtime-autosuspend-to-avoid-thrashing-V.patch
@@ -0,0 +1,78 @@
+From 5163dcd743642b47a6f82ced6dd110a669984359 Mon Sep 17 00:00:00 2001
+From: Eric Anholt <eric@anholt.net>
+Date: Fri, 4 Nov 2016 15:58:38 -0700
+Subject: [PATCH] drm/vc4: Use runtime autosuspend to avoid thrashing V3D power
+ state.
+
+The pm_runtime_put() we were using immediately released power on the
+device, which meant that we were generally turning the device off and
+on once per frame. In many profiles I've looked at, that added up to
+about 1% of CPU time, but this could get worse in the case of frequent
+rendering and readback (as may happen in X rendering). By keeping the
+device on until we've been idle for a couple of frames, we drop the
+overhead of runtime PM down to sub-.1%.
+
+Signed-off-by: Eric Anholt <eric@anholt.net>
+(cherry picked from commit 3a62234680d86efa0239665ed8a0e908f1aef147)
+---
+ drivers/gpu/drm/vc4/vc4_drv.c | 9 ++++++---
+ drivers/gpu/drm/vc4/vc4_gem.c | 6 ++++--
+ drivers/gpu/drm/vc4/vc4_v3d.c | 2 ++
+ 3 files changed, 12 insertions(+), 5 deletions(-)
+
+--- a/drivers/gpu/drm/vc4/vc4_drv.c
++++ b/drivers/gpu/drm/vc4/vc4_drv.c
+@@ -86,21 +86,24 @@ static int vc4_get_param_ioctl(struct dr
+ if (ret < 0)
+ return ret;
+ args->value = V3D_READ(V3D_IDENT0);
+- pm_runtime_put(&vc4->v3d->pdev->dev);
++ pm_runtime_mark_last_busy(&vc4->v3d->pdev->dev);
++ pm_runtime_put_autosuspend(&vc4->v3d->pdev->dev);
+ break;
+ case DRM_VC4_PARAM_V3D_IDENT1:
+ ret = pm_runtime_get_sync(&vc4->v3d->pdev->dev);
+ if (ret < 0)
+ return ret;
+ args->value = V3D_READ(V3D_IDENT1);
+- pm_runtime_put(&vc4->v3d->pdev->dev);
++ pm_runtime_mark_last_busy(&vc4->v3d->pdev->dev);
++ pm_runtime_put_autosuspend(&vc4->v3d->pdev->dev);
+ break;
+ case DRM_VC4_PARAM_V3D_IDENT2:
+ ret = pm_runtime_get_sync(&vc4->v3d->pdev->dev);
+ if (ret < 0)
+ return ret;
+ args->value = V3D_READ(V3D_IDENT2);
+- pm_runtime_put(&vc4->v3d->pdev->dev);
++ pm_runtime_mark_last_busy(&vc4->v3d->pdev->dev);
++ pm_runtime_put_autosuspend(&vc4->v3d->pdev->dev);
+ break;
+ case DRM_VC4_PARAM_SUPPORTS_BRANCHES:
+ case DRM_VC4_PARAM_SUPPORTS_ETC1:
+--- a/drivers/gpu/drm/vc4/vc4_gem.c
++++ b/drivers/gpu/drm/vc4/vc4_gem.c
+@@ -728,8 +728,10 @@ vc4_complete_exec(struct drm_device *dev
+ mutex_unlock(&dev->struct_mutex);
+
+ mutex_lock(&vc4->power_lock);
+- if (--vc4->power_refcount == 0)
+- pm_runtime_put(&vc4->v3d->pdev->dev);
++ if (--vc4->power_refcount == 0) {
++ pm_runtime_mark_last_busy(&vc4->v3d->pdev->dev);
++ pm_runtime_put_autosuspend(&vc4->v3d->pdev->dev);
++ }
+ mutex_unlock(&vc4->power_lock);
+
+ kfree(exec);
+--- a/drivers/gpu/drm/vc4/vc4_v3d.c
++++ b/drivers/gpu/drm/vc4/vc4_v3d.c
+@@ -222,6 +222,8 @@ static int vc4_v3d_bind(struct device *d
+ return ret;
+ }
+
++ pm_runtime_use_autosuspend(dev);
++ pm_runtime_set_autosuspend_delay(dev, 40); /* a little over 2 frames. */
+ pm_runtime_enable(dev);
+
+ return 0;