dma_alloc_coherent does not return a physical address, but a DMA address, which might be remapped or have an offset. Passing this DMA address to vm_iomap_memory is completely bogus. Use the proper dma_mmap_coherent helper instead, and stop passing __GFP_COMP to dma_alloc_coherent, as the memory management inside the DMA allocator is hidden from the callers. Fixes: a8f3c203e19b ("[media] videobuf-dma-contig: add cache support") Signed-off-by: Christoph Hellwig <hch@xxxxxx> --- drivers/media/v4l2-core/videobuf-dma-contig.c | 23 +++++++------------ 1 file changed, 8 insertions(+), 15 deletions(-) diff --git a/drivers/media/v4l2-core/videobuf-dma-contig.c b/drivers/media/v4l2-core/videobuf-dma-contig.c index e1bf50df4c70..a5942ea38f1f 100644 --- a/drivers/media/v4l2-core/videobuf-dma-contig.c +++ b/drivers/media/v4l2-core/videobuf-dma-contig.c @@ -39,11 +39,11 @@ struct videobuf_dma_contig_memory { static int __videobuf_dc_alloc(struct device *dev, struct videobuf_dma_contig_memory *mem, - unsigned long size, gfp_t flags) + unsigned long size) { mem->size = size; - mem->vaddr = dma_alloc_coherent(dev, mem->size, - &mem->dma_handle, flags); + mem->vaddr = dma_alloc_coherent(dev, mem->size, &mem->dma_handle, + GFP_KERNEL); if (!mem->vaddr) { dev_err(dev, "memory alloc size %ld failed\n", mem->size); @@ -260,8 +260,7 @@ static int __videobuf_iolock(struct videobuf_queue *q, return videobuf_dma_contig_user_get(mem, vb); /* allocate memory for the read() method */ - if (__videobuf_dc_alloc(q->dev, mem, PAGE_ALIGN(vb->size), - GFP_KERNEL)) + if (__videobuf_dc_alloc(q->dev, mem, PAGE_ALIGN(vb->size))) return -ENOMEM; break; case V4L2_MEMORY_OVERLAY: @@ -280,7 +279,6 @@ static int __videobuf_mmap_mapper(struct videobuf_queue *q, struct videobuf_dma_contig_memory *mem; struct videobuf_mapping *map; int retval; - unsigned long size; dev_dbg(q->dev, "%s\n", __func__); @@ -298,23 +296,18 @@ static int __videobuf_mmap_mapper(struct videobuf_queue *q, BUG_ON(!mem); MAGIC_CHECK(mem->magic, MAGIC_DC_MEM); - if (__videobuf_dc_alloc(q->dev, mem, PAGE_ALIGN(buf->bsize), - GFP_KERNEL | __GFP_COMP)) + if (__videobuf_dc_alloc(q->dev, mem, PAGE_ALIGN(buf->bsize))) goto error; - /* Try to remap memory */ - size = vma->vm_end - vma->vm_start; - vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); - /* the "vm_pgoff" is just used in v4l2 to find the * corresponding buffer data structure which is allocated * earlier and it does not mean the offset from the physical * buffer start address as usual. So set it to 0 to pass - * the sanity check in vm_iomap_memory(). + * the sanity check in dma_mmap_coherent(). */ vma->vm_pgoff = 0; - - retval = vm_iomap_memory(vma, mem->dma_handle, size); + retval = dma_mmap_coherent(q->dev, vma, mem->vaddr, mem->dma_handle, + vma->vm_end - vma->vm_start); if (retval) { dev_err(q->dev, "mmap: remap failed with error %d. ", retval); -- 2.20.1 _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel