From: Dave Airlie airlied@redhat.com
In order for udl vmap to work properly, we need to push the object into the CPU domain before we start copying the data to the USB device.
question: what is direction here in terms of read/write to the device.
This along with the udl change avoids userspace explicit mapping to be used.
Signed-off-by: Dave Airlie airlied@redhat.com --- drivers/gpu/drm/i915/i915_gem_dmabuf.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+)
diff --git a/drivers/gpu/drm/i915/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/i915_gem_dmabuf.c index cf6bdec..ee51c63 100644 --- a/drivers/gpu/drm/i915/i915_gem_dmabuf.c +++ b/drivers/gpu/drm/i915/i915_gem_dmabuf.c @@ -147,6 +147,22 @@ static int i915_gem_dmabuf_mmap(struct dma_buf *dma_buf, struct vm_area_struct * return -EINVAL; }
+static int i915_gem_begin_cpu_access(struct dma_buf *dma_buf, size_t start, size_t length, enum dma_data_direction direction) +{ + struct drm_i915_gem_object *obj = dma_buf->priv; + struct drm_device *dev = obj->base.dev; + int ret; + bool write = (direction == DMA_BIDIRECTIONAL || direction == DMA_TO_DEVICE); + + ret = i915_mutex_lock_interruptible(dev); + if (ret) + return ret; + + ret = i915_gem_object_set_to_cpu_domain(obj, write); + mutex_unlock(&dev->struct_mutex); + return ret; +} + static const struct dma_buf_ops i915_dmabuf_ops = { .map_dma_buf = i915_gem_map_dma_buf, .unmap_dma_buf = i915_gem_unmap_dma_buf, @@ -158,6 +174,7 @@ static const struct dma_buf_ops i915_dmabuf_ops = { .mmap = i915_gem_dmabuf_mmap, .vmap = i915_gem_dmabuf_vmap, .vunmap = i915_gem_dmabuf_vunmap, + .begin_cpu_access = i915_gem_begin_cpu_access, };
struct dma_buf *i915_gem_prime_export(struct drm_device *dev,