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

[Sean Paul]

On Fri, Nov 11, 2016 at 9:15 AM, Gustavo Padovan <gustavo@xxxxxxxxxxx> wrote:
> From: Gustavo Padovan <gustavo.padovan@xxxxxxxxxxxxxxx>
>
> 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@xxxxxxxxxxxxxxx>
> Reviewed-by: Brian Starkey <brian.starkey@xxxxxxx>

Reviewed-by: Sean Paul <seanpaul@xxxxxxxxxxxx>

> ---
>  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
>