Re: [PATCH v8 1/3] drm/fence: add in-fences support

Brian Starkey
2016-11-11T10:47:58Z

Hi Gustavo,

On Fri, Nov 11, 2016 at 02:16:07PM +0900, Gustavo Padovan wrote:
>From: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
>
>There is now a new property called IN_FENCE_FD attached to every plane
>state that receives sync_file fds from userspace via the atomic commit
>IOCTL.
>
>The fd is then translated to a fence (that may be a fence_array
>subclass or just a normal fence) and then used by DRM to fence_wait() for
>all fences in the sync_file to signal. So it only commits when all
>framebuffers are ready to scanout.
>
>v2: Comments by Daniel Vetter:
> - remove set state->fence = NULL in destroy phase
> - accept fence -1 as valid and just return 0
> - do not call fence_get() - sync_file_fences_get() already calls it
> - fence_put() if state->fence is already set, in case userspace
> set the property more than once.
>
>v3: WARN_ON if fence is set but state has no FB
>
>v4: Comment from Maarten Lankhorst
> - allow set fence with no related fb
>
>v5: rename FENCE_FD to IN_FENCE_FD
>
>v6: Comments by Daniel Vetter:
> - rename plane_state->in_fence back to "fence"
> - re-introduce WARN_ON if fence set but no fb
>
> - rebase after fence -> dma_fence rename
>
>v7: Comments by Brian Starkey
> - set state->fence to NULL when duplicating the state
> - fail if IN_FENCE_FD was already set
>
>Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>

lgtm,

Reviewed-by: Brian Starkey <brian.starkey@arm.com>

>---
> drivers/gpu/drm/Kconfig | 1 +
> drivers/gpu/drm/drm_atomic.c | 14 ++++++++++++++
> drivers/gpu/drm/drm_atomic_helper.c | 5 +++++
> drivers/gpu/drm/drm_crtc.c | 6 ++++++
> drivers/gpu/drm/drm_plane.c | 1 +
> include/drm/drm_crtc.h | 5 +++++
> 6 files changed, 32 insertions(+)
>
>diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
>index 25e8e37..360cb92 100644
>--- a/drivers/gpu/drm/Kconfig
>+++ b/drivers/gpu/drm/Kconfig
>@@ -12,6 +12,7 @@ menuconfig DRM
> select I2C
> select I2C_ALGOBIT
> select DMA_SHARED_BUFFER
>+ select SYNC_FILE
> help
> Kernel-level support for the Direct Rendering Infrastructure (DRI)
> introduced in XFree86 4.0. If you say Y here, you need to select
>diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
>index b096c16..8e26ad1 100644
>--- a/drivers/gpu/drm/drm_atomic.c
>+++ b/drivers/gpu/drm/drm_atomic.c
>@@ -31,6 +31,7 @@
> #include <drm/drm_mode.h>
> #include <drm/drm_plane_helper.h>
> #include <drm/drm_print.h>
>+#include <linux/sync_file.h>
>
> #include "drm_crtc_internal.h"
>
>@@ -709,6 +710,17 @@ int drm_atomic_plane_set_property(struct drm_plane *plane,
> drm_atomic_set_fb_for_plane(state, fb);
> if (fb)
> drm_framebuffer_unreference(fb);
>+ } else if (property == config->prop_in_fence_fd) {
>+ if (state->fence)
>+ return -EINVAL;
>+
>+ if (U642I64(val) == -1)
>+ return 0;
>+
>+ state->fence = sync_file_get_fence(val);
>+ if (!state->fence)
>+ return -EINVAL;
>+
> } else if (property == config->prop_crtc_id) {
> struct drm_crtc *crtc = drm_crtc_find(dev, val);
> return drm_atomic_set_crtc_for_plane(state, crtc);
>@@ -770,6 +782,8 @@ drm_atomic_plane_get_property(struct drm_plane *plane,
>
> if (property == config->prop_fb_id) {
> *val = (state->fb) ? state->fb->base.id : 0;
>+ } else if (property == config->prop_in_fence_fd) {
>+ *val = -1;
> } else if (property == config->prop_crtc_id) {
> *val = (state->crtc) ? state->crtc->base.id : 0;
> } else if (property == config->prop_crtc_x) {
>diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
>index 75ad01d..caed870 100644
>--- a/drivers/gpu/drm/drm_atomic_helper.c
>+++ b/drivers/gpu/drm/drm_atomic_helper.c
>@@ -3076,6 +3076,8 @@ void __drm_atomic_helper_plane_duplicate_state(struct drm_plane *plane,
>
> if (state->fb)
> drm_framebuffer_reference(state->fb);
>+
>+ state->fence = NULL;
> }
> EXPORT_SYMBOL(__drm_atomic_helper_plane_duplicate_state);
>
>@@ -3114,6 +3116,9 @@ void __drm_atomic_helper_plane_destroy_state(struct drm_plane_state *state)
> {
> if (state->fb)
> drm_framebuffer_unreference(state->fb);
>+
>+ if (state->fence)
>+ dma_fence_put(state->fence);
> }
> EXPORT_SYMBOL(__drm_atomic_helper_plane_destroy_state);
>
>diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
>index ce274ed..154e040 100644
>--- a/drivers/gpu/drm/drm_crtc.c
>+++ b/drivers/gpu/drm/drm_crtc.c
>@@ -397,6 +397,12 @@ static int drm_mode_create_standard_properties(struct drm_device *dev)
> return -ENOMEM;
> dev->mode_config.prop_fb_id = prop;
>
>+ prop = drm_property_create_signed_range(dev, DRM_MODE_PROP_ATOMIC,
>+ "IN_FENCE_FD", -1, INT_MAX);
>+ if (!prop)
>+ return -ENOMEM;
>+ dev->mode_config.prop_in_fence_fd = prop;
>+
> prop = drm_property_create_object(dev, DRM_MODE_PROP_ATOMIC,
> "CRTC_ID", DRM_MODE_OBJECT_CRTC);
> if (!prop)
>diff --git a/drivers/gpu/drm/drm_plane.c b/drivers/gpu/drm/drm_plane.c
>index 249c0ae..3957ef8 100644
>--- a/drivers/gpu/drm/drm_plane.c
>+++ b/drivers/gpu/drm/drm_plane.c
>@@ -137,6 +137,7 @@ int drm_universal_plane_init(struct drm_device *dev, struct drm_plane *plane,
>
> if (drm_core_check_feature(dev, DRIVER_ATOMIC)) {
> drm_object_attach_property(&plane->base, config->prop_fb_id, 0);
>+ drm_object_attach_property(&plane->base, config->prop_in_fence_fd, -1);
> drm_object_attach_property(&plane->base, config->prop_crtc_id, 0);
> drm_object_attach_property(&plane->base, config->prop_crtc_x, 0);
> drm_object_attach_property(&plane->base, config->prop_crtc_y, 0);
>diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
>index 8cca2a8..11780a9 100644
>--- a/include/drm/drm_crtc.h
>+++ b/include/drm/drm_crtc.h
>@@ -1214,6 +1214,11 @@ struct drm_mode_config {
> */
> struct drm_property *prop_fb_id;
> /**
>+ * @prop_in_fence_fd: Sync File fd representing the incoming fences
>+ * for a Plane.
>+ */
>+ struct drm_property *prop_in_fence_fd;
>+ /**
> * @prop_crtc_id: Default atomic plane property to specify the
> * &drm_crtc.
> */
>--
>2.5.5
>