V4L/DVB (6058): ivtv: add support for highmem udma

When trying to DMA userspace buffers to the cx23415 you need to check
whether the page is in highmem. If this is the case, then bounce buffers
have to be used to allow DMA.

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

1 files changed, 8 insertions, 1 deletions

diff --git a/drivers/media/video/ivtv/ivtv-yuv.c b/drivers/media/video/ivtv/ivtv-yuv.c
index fa8c76f3d359..2ae7556f5e68 100644
--- a/drivers/media/video/ivtv/ivtv-yuv.c
+++ b/drivers/media/video/ivtv/ivtv-yuv.c
@@ -83,7 +83,14 @@ static int ivtv_yuv_prep_user_dma(struct ivtv *itv, struct ivtv_user_dma *dma,
         }
 
         /* Fill & map SG List */
-        ivtv_udma_fill_sg_list (dma, &uv_dma, ivtv_udma_fill_sg_list (dma, &y_dma, 0));
+        if (ivtv_udma_fill_sg_list (dma, &uv_dma, ivtv_udma_fill_sg_list (dma, &y_dma, 0))) {
+                IVTV_DEBUG_WARN("could not allocate bounce buffers for highmem userspace buffers\n");
+                for (i = 0; i < dma->page_count; i++) {
+                        put_page(dma->map[i]);
+                }
+                dma->page_count = 0;
+                return -ENOMEM;
+        }
         dma->SG_length = pci_map_sg(itv->dev, dma->SGlist, dma->page_count, PCI_DMA_TODEVICE);
 
         /* Fill SG Array with new values */