diff options
| -rw-r--r-- | drivers/gpu/drm/drm_atomic_uapi.c | 47 | ||||
| -rw-r--r-- | drivers/gpu/drm/drm_gem_atomic_helper.c | 73 | ||||
| -rw-r--r-- | include/drm/drm_atomic_uapi.h | 2 | ||||
| -rw-r--r-- | include/drm/drm_plane.h | 4 |
4 files changed, 62 insertions, 64 deletions
diff --git a/drivers/gpu/drm/drm_atomic_uapi.c b/drivers/gpu/drm/drm_atomic_uapi.c index c6394ba13b24..434f3d4cb8a2 100644 --- a/drivers/gpu/drm/drm_atomic_uapi.c +++ b/drivers/gpu/drm/drm_atomic_uapi.c @@ -255,43 +255,6 @@ drm_atomic_set_fb_for_plane(struct drm_plane_state *plane_state, EXPORT_SYMBOL(drm_atomic_set_fb_for_plane); /** - * drm_atomic_set_fence_for_plane - set fence for plane - * @plane_state: atomic state object for the plane - * @fence: dma_fence to use for the plane - * - * Helper to setup the plane_state fence in case it is not set yet. - * By using this drivers doesn't need to worry if the user choose - * implicit or explicit fencing. - * - * This function will not set the fence to the state if it was set - * via explicit fencing interfaces on the atomic ioctl. In that case it will - * drop the reference to the fence as we are not storing it anywhere. - * Otherwise, if &drm_plane_state.fence is not set this function we just set it - * with the received implicit fence. In both cases this function consumes a - * reference for @fence. - * - * This way explicit fencing can be used to overrule implicit fencing, which is - * important to make explicit fencing use-cases work: One example is using one - * buffer for 2 screens with different refresh rates. Implicit fencing will - * clamp rendering to the refresh rate of the slower screen, whereas explicit - * fence allows 2 independent render and display loops on a single buffer. If a - * driver allows obeys both implicit and explicit fences for plane updates, then - * it will break all the benefits of explicit fencing. - */ -void -drm_atomic_set_fence_for_plane(struct drm_plane_state *plane_state, - struct dma_fence *fence) -{ - if (plane_state->fence) { - dma_fence_put(fence); - return; - } - - plane_state->fence = fence; -} -EXPORT_SYMBOL(drm_atomic_set_fence_for_plane); - -/** * drm_atomic_set_crtc_for_connector - set CRTC for connector * @conn_state: atomic state object for the connector * @crtc: CRTC to use for the connector @@ -1077,10 +1040,10 @@ int drm_atomic_set_property(struct drm_atomic_state *state, * * As a contrast, with implicit fencing the kernel keeps track of any * ongoing rendering, and automatically ensures that the atomic update waits - * for any pending rendering to complete. For shared buffers represented with - * a &struct dma_buf this is tracked in &struct dma_resv. - * Implicit syncing is how Linux traditionally worked (e.g. DRI2/3 on X.org), - * whereas explicit fencing is what Android wants. + * for any pending rendering to complete. This is usually tracked in &struct + * dma_resv which can also contain mandatory kernel fences. Implicit syncing + * is how Linux traditionally worked (e.g. DRI2/3 on X.org), whereas explicit + * fencing is what Android wants. * * "IN_FENCE_FD”: * Use this property to pass a fence that DRM should wait on before @@ -1095,7 +1058,7 @@ int drm_atomic_set_property(struct drm_atomic_state *state, * * On the driver side the fence is stored on the @fence parameter of * &struct drm_plane_state. Drivers which also support implicit fencing - * should set the implicit fence using drm_atomic_set_fence_for_plane(), + * should extract the implicit fence using drm_gem_plane_helper_prepare_fb(), * to make sure there's consistent behaviour between drivers in precedence * of implicit vs. explicit fencing. * diff --git a/drivers/gpu/drm/drm_gem_atomic_helper.c b/drivers/gpu/drm/drm_gem_atomic_helper.c index a6d89aed0bda..a5026f617739 100644 --- a/drivers/gpu/drm/drm_gem_atomic_helper.c +++ b/drivers/gpu/drm/drm_gem_atomic_helper.c @@ -1,6 +1,7 @@ // SPDX-License-Identifier: GPL-2.0-or-later #include <linux/dma-resv.h> +#include <linux/dma-fence-chain.h> #include <drm/drm_atomic_state_helper.h> #include <drm/drm_atomic_uapi.h> @@ -137,29 +138,67 @@ * * This function is the default implementation for GEM drivers of * &drm_plane_helper_funcs.prepare_fb if no callback is provided. - * - * See drm_atomic_set_fence_for_plane() for a discussion of implicit and - * explicit fencing in atomic modeset updates. */ -int drm_gem_plane_helper_prepare_fb(struct drm_plane *plane, struct drm_plane_state *state) +int drm_gem_plane_helper_prepare_fb(struct drm_plane *plane, + struct drm_plane_state *state) { - struct drm_gem_object *obj; - struct dma_fence *fence; + struct dma_fence *fence = dma_fence_get(state->fence); + enum dma_resv_usage usage; + size_t i; int ret; if (!state->fb) return 0; - obj = drm_gem_fb_get_obj(state->fb, 0); - ret = dma_resv_get_singleton(obj->resv, DMA_RESV_USAGE_WRITE, &fence); - if (ret) - return ret; - - /* TODO: drm_atomic_set_fence_for_plane() should be changed to be able - * to handle more fences in general for multiple BOs per fb. + /* + * Only add the kernel fences here if there is already a fence set via + * explicit fencing interfaces on the atomic ioctl. + * + * This way explicit fencing can be used to overrule implicit fencing, + * which is important to make explicit fencing use-cases work: One + * example is using one buffer for 2 screens with different refresh + * rates. Implicit fencing will clamp rendering to the refresh rate of + * the slower screen, whereas explicit fence allows 2 independent + * render and display loops on a single buffer. If a driver allows + * obeys both implicit and explicit fences for plane updates, then it + * will break all the benefits of explicit fencing. */ - drm_atomic_set_fence_for_plane(state, fence); + usage = fence ? DMA_RESV_USAGE_KERNEL : DMA_RESV_USAGE_WRITE; + + for (i = 0; i < state->fb->format->num_planes; ++i) { + struct drm_gem_object *obj = drm_gem_fb_get_obj(state->fb, i); + struct dma_fence *new; + + if (WARN_ON_ONCE(!obj)) + continue; + + ret = dma_resv_get_singleton(obj->resv, usage, &new); + if (ret) + goto error; + + if (new && fence) { + struct dma_fence_chain *chain = dma_fence_chain_alloc(); + + if (!chain) { + ret = -ENOMEM; + goto error; + } + + dma_fence_chain_init(chain, fence, new, 1); + fence = &chain->base; + + } else if (new) { + fence = new; + } + } + + dma_fence_put(state->fence); + state->fence = fence; return 0; + +error: + dma_fence_put(fence); + return ret; } EXPORT_SYMBOL_GPL(drm_gem_plane_helper_prepare_fb); @@ -168,13 +207,13 @@ EXPORT_SYMBOL_GPL(drm_gem_plane_helper_prepare_fb); * @pipe: Simple display pipe * @plane_state: Plane state * - * This function uses drm_gem_plane_helper_prepare_fb() to extract the exclusive fence - * from &drm_gem_object.resv and attaches it to plane state for the atomic + * This function uses drm_gem_plane_helper_prepare_fb() to extract the fences + * from &drm_gem_object.resv and attaches them to the plane state for the atomic * helper to wait on. This is necessary to correctly implement implicit * synchronization for any buffers shared as a struct &dma_buf. Drivers can use * this as their &drm_simple_display_pipe_funcs.prepare_fb callback. * - * See drm_atomic_set_fence_for_plane() for a discussion of implicit and + * See drm_gem_plane_helper_prepare_fb() for a discussion of implicit and * explicit fencing in atomic modeset updates. */ int drm_gem_simple_display_pipe_prepare_fb(struct drm_simple_display_pipe *pipe, diff --git a/include/drm/drm_atomic_uapi.h b/include/drm/drm_atomic_uapi.h index 8cec52ad1277..4c6d39d7bdb2 100644 --- a/include/drm/drm_atomic_uapi.h +++ b/include/drm/drm_atomic_uapi.h @@ -49,8 +49,6 @@ drm_atomic_set_crtc_for_plane(struct drm_plane_state *plane_state, struct drm_crtc *crtc); void drm_atomic_set_fb_for_plane(struct drm_plane_state *plane_state, struct drm_framebuffer *fb); -void drm_atomic_set_fence_for_plane(struct drm_plane_state *plane_state, - struct dma_fence *fence); int __must_check drm_atomic_set_crtc_for_connector(struct drm_connector_state *conn_state, struct drm_crtc *crtc); diff --git a/include/drm/drm_plane.h b/include/drm/drm_plane.h index 2628c7cde2da..89ea54652e87 100644 --- a/include/drm/drm_plane.h +++ b/include/drm/drm_plane.h @@ -74,9 +74,7 @@ struct drm_plane_state { * * Optional fence to wait for before scanning out @fb. The core atomic * code will set this when userspace is using explicit fencing. Do not - * write this field directly for a driver's implicit fence, use - * drm_atomic_set_fence_for_plane() to ensure that an explicit fence is - * preserved. + * write this field directly for a driver's implicit fence. * * Drivers should store any implicit fence in this from their * &drm_plane_helper_funcs.prepare_fb callback. See drm_gem_plane_helper_prepare_fb() |