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Commit 1010ed13 authored by Cohen David.A's avatar Cohen David.A Committed by Mauro Carvalho Chehab
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V4L/DVB (11840): change kmalloc to vmalloc for sglist allocation in videobuf_dma_map/unmap 



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: default avatarDavid Cohen <david.cohen@nokia.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@redhat.com>
parent 04a37e0f

Documentation/video4linux/CARDLIST.em28xx

+2 −0
Original line number Diff line number Diff line
@@ -62,3 +62,5 @@ 
 64 -> Easy Cap Capture DC-60                   (em2860)

 65 -> IO-DATA GV-MVP/SZ                        (em2820/em2840) [04bb:0515]

 66 -> Empire dual TV                           (em2880)

 67 -> Terratec Grabby                          (em2860)        [0ccd:0096]

 68 -> Terratec AV350                           (em2860)        [0ccd:0084]

drivers/media/video/videobuf-dma-sg.c

+9 −8
Original line number Diff line number Diff line
@@ -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;