Hi Tomasz, Thanks for the patch. On Wednesday 10 October 2012 16:46:40 Tomasz Stanislawski wrote: > This patch adds taking reference to the device for MMAP buffers. > > Such buffers, may be exported using DMABUF mechanism. If the driver that > created a queue is unloaded then the queue is released, the device might be > released too. However, buffers cannot be released if they are referenced by > DMABUF descriptor(s). The device pointer kept in a buffer must be valid for > the whole buffer's lifetime. Therefore MMAP buffers should take a reference > to the device to avoid risk of dangling pointers. > > Signed-off-by: Tomasz Stanislawski <t.stanislaws@xxxxxxxxxxx> > Acked-by: Hans Verkuil <hans.verkuil@xxxxxxxxx> Acked-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> But two small comments below. > --- > drivers/media/v4l2-core/videobuf2-dma-contig.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/media/v4l2-core/videobuf2-dma-contig.c > b/drivers/media/v4l2-core/videobuf2-dma-contig.c index b138b5c..2d661fd > 100644 > --- a/drivers/media/v4l2-core/videobuf2-dma-contig.c > +++ b/drivers/media/v4l2-core/videobuf2-dma-contig.c > @@ -148,6 +148,7 @@ static void vb2_dc_put(void *buf_priv) > kfree(buf->sgt_base); > } > dma_free_coherent(buf->dev, buf->size, buf->vaddr, buf->dma_addr); > + put_device(buf->dev); > kfree(buf); > } > > @@ -168,6 +169,9 @@ static void *vb2_dc_alloc(void *alloc_ctx, unsigned long > size) return ERR_PTR(-ENOMEM); > } > > + /* prevent the device from release while the buffer is exported */ s/prevent/Prevent/ ? > + get_device(dev); > + > buf->dev = dev; What about just buf->dev = get_device(dev); > buf->size = size; -- Regards, Laurent Pinchart -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
