On Thu, May 14, 2009 at 09:04:48AM +0200, Cohen David.A (Nokia-D/Helsinki) wrote:
> From: Cohen David.A (Nokia-D/Helsinki) <david.cohen@xxxxxxxxx>
>
> Change kmalloc()/kfree() to vmalloc()/vfree() for sglist allocation
> during videobuf_dma_map() and videobuf_dma_unmap()
>
> High resolution sensors might require too many contiguous pages
> to be allocated for sglist by kmalloc() during videobuf_dma_map()
> (i.e. 256Kib for 8MP sensor).
> In such situations, kmalloc() could face some problem to find the
> required free memory. vmalloc() is a safer solution instead, as the
> allocated memory does not need to be contiguous.
>
> Signed-off-by: David Cohen <david.cohen@xxxxxxxxx>
> ---
> drivers/media/video/videobuf-dma-sg.c | 17 +++++++++--------
> 1 files changed, 9 insertions(+), 8 deletions(-)
Hi Mauro,
Any comments?
Br,
David Cohen
>
> diff --git a/drivers/media/video/videobuf-dma-sg.c b/drivers/media/video/videobuf-dma-sg.c
> index da1790e..c9a5d7e 100644
> --- a/drivers/media/video/videobuf-dma-sg.c
> +++ b/drivers/media/video/videobuf-dma-sg.c
> @@ -58,9 +58,10 @@ videobuf_vmalloc_to_sg(unsigned char *virt, int nr_pages)
> struct page *pg;
> int i;
>
> - sglist = kcalloc(nr_pages, sizeof(struct scatterlist), GFP_KERNEL);
> + sglist = vmalloc(nr_pages * sizeof(*sglist));
> if (NULL == sglist)
> return NULL;
> + memset(sglist, 0, nr_pages * sizeof(*sglist));
> sg_init_table(sglist, nr_pages);
> for (i = 0; i < nr_pages; i++, virt += PAGE_SIZE) {
> pg = vmalloc_to_page(virt);
> @@ -72,7 +73,7 @@ videobuf_vmalloc_to_sg(unsigned char *virt, int nr_pages)
> return sglist;
>
> err:
> - kfree(sglist);
> + vfree(sglist);
> return NULL;
> }
>
> @@ -84,7 +85,7 @@ videobuf_pages_to_sg(struct page **pages, int nr_pages, int offset)
>
> if (NULL == pages[0])
> return NULL;
> - sglist = kmalloc(nr_pages * sizeof(*sglist), GFP_KERNEL);
> + sglist = vmalloc(nr_pages * sizeof(*sglist));
> if (NULL == sglist)
> return NULL;
> sg_init_table(sglist, nr_pages);
> @@ -104,12 +105,12 @@ videobuf_pages_to_sg(struct page **pages, int nr_pages, int offset)
>
> nopage:
> dprintk(2,"sgl: oops - no page\n");
> - kfree(sglist);
> + vfree(sglist);
> return NULL;
>
> highmem:
> dprintk(2,"sgl: oops - highmem page\n");
> - kfree(sglist);
> + vfree(sglist);
> return NULL;
> }
>
> @@ -230,7 +231,7 @@ int videobuf_dma_map(struct videobuf_queue* q, struct videobuf_dmabuf *dma)
> (dma->vmalloc,dma->nr_pages);
> }
> if (dma->bus_addr) {
> - dma->sglist = kmalloc(sizeof(struct scatterlist), GFP_KERNEL);
> + dma->sglist = vmalloc(sizeof(*dma->sglist));
> if (NULL != dma->sglist) {
> dma->sglen = 1;
> sg_dma_address(&dma->sglist[0]) = dma->bus_addr & PAGE_MASK;
> @@ -248,7 +249,7 @@ int videobuf_dma_map(struct videobuf_queue* q, struct videobuf_dmabuf *dma)
> if (0 == dma->sglen) {
> printk(KERN_WARNING
> "%s: videobuf_map_sg failed\n",__func__);
> - kfree(dma->sglist);
> + vfree(dma->sglist);
> dma->sglist = NULL;
> dma->sglen = 0;
> return -EIO;
> @@ -274,7 +275,7 @@ int videobuf_dma_unmap(struct videobuf_queue* q,struct videobuf_dmabuf *dma)
>
> dma_unmap_sg(q->dev, dma->sglist, dma->nr_pages, dma->direction);
>
> - kfree(dma->sglist);
> + vfree(dma->sglist);
> dma->sglist = NULL;
> dma->sglen = 0;
> return 0;
> --
> 1.6.1
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