| Message ID | 20210622165511.3169559-7-daniel.vetter@ffwll.ch (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | implicit fencing/dma-resv rules for shared buffers | expand |
On Tue, 22 Jun 2021 18:55:02 +0200 Daniel Vetter <daniel.vetter@ffwll.ch> wrote: > Currently this has no practial relevance I think because there's not > many who can pull off a setup with panfrost and another gpu in the > same system. But the rules are that if you're setting an exclusive > fence, indicating a gpu write access in the implicit fencing system, > then you need to wait for all fences, not just the previous exclusive > fence. > > panfrost against itself has no problem, because it always sets the > exclusive fence (but that's probably something that will need to be > fixed for vulkan and/or multi-engine gpus, or you'll suffer badly). > Also no problem with that against display. > > With the prep work done to switch over to the dependency helpers this > is now a oneliner. > > Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> > Cc: Rob Herring <robh@kernel.org> > Cc: Tomeu Vizoso <tomeu.vizoso@collabora.com> > Cc: Steven Price <steven.price@arm.com> > Cc: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com> > Cc: Sumit Semwal <sumit.semwal@linaro.org> Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com> > Cc: "Christian König" <christian.koenig@amd.com> > Cc: linux-media@vger.kernel.org > Cc: linaro-mm-sig@lists.linaro.org > --- > drivers/gpu/drm/panfrost/panfrost_job.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/panfrost/panfrost_job.c b/drivers/gpu/drm/panfrost/panfrost_job.c > index 71cd43fa1b36..ef004d587dc4 100644 > --- a/drivers/gpu/drm/panfrost/panfrost_job.c > +++ b/drivers/gpu/drm/panfrost/panfrost_job.c > @@ -203,9 +203,8 @@ static int panfrost_acquire_object_fences(struct drm_gem_object **bos, > int i, ret; > > for (i = 0; i < bo_count; i++) { > - struct dma_fence *fence = dma_resv_get_excl_unlocked(bos[i]->resv); > - > - ret = drm_gem_fence_array_add(deps, fence); > + /* panfrost always uses write mode in its current uapi */ > + ret = drm_gem_fence_array_add_implicit(deps, bos[i], true); > if (ret) > return ret; > }
On Wed, Jun 23, 2021 at 06:47:37PM +0200, Boris Brezillon wrote: > On Tue, 22 Jun 2021 18:55:02 +0200 > Daniel Vetter <daniel.vetter@ffwll.ch> wrote: > > > Currently this has no practial relevance I think because there's not > > many who can pull off a setup with panfrost and another gpu in the > > same system. But the rules are that if you're setting an exclusive > > fence, indicating a gpu write access in the implicit fencing system, > > then you need to wait for all fences, not just the previous exclusive > > fence. > > > > panfrost against itself has no problem, because it always sets the > > exclusive fence (but that's probably something that will need to be > > fixed for vulkan and/or multi-engine gpus, or you'll suffer badly). > > Also no problem with that against display. > > > > With the prep work done to switch over to the dependency helpers this > > is now a oneliner. > > > > Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> > > Cc: Rob Herring <robh@kernel.org> > > Cc: Tomeu Vizoso <tomeu.vizoso@collabora.com> > > Cc: Steven Price <steven.price@arm.com> > > Cc: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com> > > Cc: Sumit Semwal <sumit.semwal@linaro.org> > > Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com> Pushed the 3 panfrost patches to drm-misc-next, thanks for reviewing them. -Daniel > > > Cc: "Christian König" <christian.koenig@amd.com> > > Cc: linux-media@vger.kernel.org > > Cc: linaro-mm-sig@lists.linaro.org > > --- > > drivers/gpu/drm/panfrost/panfrost_job.c | 5 ++--- > > 1 file changed, 2 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/gpu/drm/panfrost/panfrost_job.c b/drivers/gpu/drm/panfrost/panfrost_job.c > > index 71cd43fa1b36..ef004d587dc4 100644 > > --- a/drivers/gpu/drm/panfrost/panfrost_job.c > > +++ b/drivers/gpu/drm/panfrost/panfrost_job.c > > @@ -203,9 +203,8 @@ static int panfrost_acquire_object_fences(struct drm_gem_object **bos, > > int i, ret; > > > > for (i = 0; i < bo_count; i++) { > > - struct dma_fence *fence = dma_resv_get_excl_unlocked(bos[i]->resv); > > - > > - ret = drm_gem_fence_array_add(deps, fence); > > + /* panfrost always uses write mode in its current uapi */ > > + ret = drm_gem_fence_array_add_implicit(deps, bos[i], true); > > if (ret) > > return ret; > > } >
diff --git a/drivers/gpu/drm/panfrost/panfrost_job.c b/drivers/gpu/drm/panfrost/panfrost_job.c index 71cd43fa1b36..ef004d587dc4 100644 --- a/drivers/gpu/drm/panfrost/panfrost_job.c +++ b/drivers/gpu/drm/panfrost/panfrost_job.c @@ -203,9 +203,8 @@ static int panfrost_acquire_object_fences(struct drm_gem_object **bos, int i, ret; for (i = 0; i < bo_count; i++) { - struct dma_fence *fence = dma_resv_get_excl_unlocked(bos[i]->resv); - - ret = drm_gem_fence_array_add(deps, fence); + /* panfrost always uses write mode in its current uapi */ + ret = drm_gem_fence_array_add_implicit(deps, bos[i], true); if (ret) return ret; }
Currently this has no practial relevance I think because there's not many who can pull off a setup with panfrost and another gpu in the same system. But the rules are that if you're setting an exclusive fence, indicating a gpu write access in the implicit fencing system, then you need to wait for all fences, not just the previous exclusive fence. panfrost against itself has no problem, because it always sets the exclusive fence (but that's probably something that will need to be fixed for vulkan and/or multi-engine gpus, or you'll suffer badly). Also no problem with that against display. With the prep work done to switch over to the dependency helpers this is now a oneliner. Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Cc: Rob Herring <robh@kernel.org> Cc: Tomeu Vizoso <tomeu.vizoso@collabora.com> Cc: Steven Price <steven.price@arm.com> Cc: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: "Christian König" <christian.koenig@amd.com> Cc: linux-media@vger.kernel.org Cc: linaro-mm-sig@lists.linaro.org --- drivers/gpu/drm/panfrost/panfrost_job.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)