diff options
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.patch | 78 |
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; |