From: Dave Airlie <airl...@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 at 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,
--
1.7.10.2
