On Tue, 22 May 2012 13:34:38 +0100, Dave Airlie <airlied@xxxxxxxxx> wrote: > From: Dave Airlie <airlied@xxxxxxxxxx> Inline comment for one sentence that made no sense. > Signed-off-by: Dave Airlie <airlied@xxxxxxxxxx> > --- > Documentation/dma-buf-sharing.txt | 11 +++++++++++ > 1 files changed, 11 insertions(+), 0 deletions(-) > > diff --git a/Documentation/dma-buf-sharing.txt b/Documentation/dma-buf-sharing.txt > index 3bbd5c5..98e9fa0 100644 > --- a/Documentation/dma-buf-sharing.txt > +++ b/Documentation/dma-buf-sharing.txt > @@ -300,6 +300,17 @@ Access to a dma_buf from the kernel context involves three steps: > Note that these calls need to always succeed. The exporter needs to complete > any preparations that might fail in begin_cpu_access. > > + For some circumstances the overhead of kmap can be too high, a vmap interface > + is introduced. This interface shouldn't be used very carefully, as vmalloc This interface should be used carefully. Sparingly would also be appropriate, though in less regular usage than carefully. > + space is a limited resources on many architectures. > + > + Interfaces: > + void *dma_buf_vmap(struct dma_buf *dmabuf) > + void dma_buf_vunmap(struct dma_buf *dmabuf, void *vaddr) > + > + This call can fail if there is no vmap support in the exporter, or if it > + runs out of vmalloc space. Fallback to kmap should be implemented. > + > 3. Finish access -- Chris Wilson, Intel Open Source Technology Centre _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
