[media] videobuf-dma-contig: restore buffer mapping for uncached bufers

from commit a8f3c203e19b702fa5e8e83a9b6fb3c5a6d1cce4
restore the mapping scheme for uncached buffers,
which was changed in a common scheme for cached and uncached.
This apparently was wrong, and was probably intended only for cached buffers.
the fix fixes the crash observed while mapping uncached buffers.

Signed-off-by: Lad, Prabhakar <prabhakar.lad@ti.com>
Signed-off-by: Hadli, Manjunath <manjunath.hadli@ti.com>
Acked-by: Federico Vaga <federico.vaga@gmail.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Cc: stable@kernel.org
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 32 insertions, 21 deletions

diff --git a/drivers/media/video/videobuf-dma-contig.c b/drivers/media/video/videobuf-dma-contig.c
index 9b9a06fdd0f0..f68284655f20 100644
--- a/drivers/media/video/videobuf-dma-contig.c
+++ b/drivers/media/video/videobuf-dma-contig.c
@@ -359,32 +359,43 @@ static int __videobuf_mmap_mapper(struct videobuf_queue *q,
         size = vma->vm_end - vma->vm_start;
         size = (size < mem->size) ? size : mem->size;
 
-        if (!mem->cached)
+        if (!mem->cached) {
                 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
-
-        pos = (unsigned long)mem->vaddr;
-
-        while (size > 0) {
-                page = virt_to_page((void *)pos);
-                if (NULL == page) {
-                        dev_err(q->dev, "mmap: virt_to_page failed\n");
-                        __videobuf_dc_free(q->dev, mem);
-                        goto error;
-                }
-                retval = vm_insert_page(vma, start, page);
+                retval = remap_pfn_range(vma, vma->vm_start,
+                         mem->dma_handle >> PAGE_SHIFT,
+                                 size, vma->vm_page_prot);
                 if (retval) {
-                        dev_err(q->dev, "mmap: insert failed with error %d\n",
-                                retval);
-                        __videobuf_dc_free(q->dev, mem);
+                        dev_err(q->dev, "mmap: remap failed with error %d. ",
+                                                                retval);
+                        dma_free_coherent(q->dev, mem->size,
+                                        mem->vaddr, mem->dma_handle);
                         goto error;
                 }
-                start += PAGE_SIZE;
-                pos += PAGE_SIZE;
+        } else {
+                pos = (unsigned long)mem->vaddr;
+
+                while (size > 0) {
+                        page = virt_to_page((void *)pos);
+                        if (NULL == page) {
+                                dev_err(q->dev, "mmap: virt_to_page failed\n");
+                                __videobuf_dc_free(q->dev, mem);
+                                goto error;
+                        }
+                        retval = vm_insert_page(vma, start, page);
+                        if (retval) {
+                                dev_err(q->dev, "mmap: insert failed with error %d\n",
+                                        retval);
+                                __videobuf_dc_free(q->dev, mem);
+                                goto error;
+                        }
+                        start += PAGE_SIZE;
+                        pos += PAGE_SIZE;
 
-                if (size > PAGE_SIZE)
-                        size -= PAGE_SIZE;
-                else
-                        size = 0;
+                        if (size > PAGE_SIZE)
+                                size -= PAGE_SIZE;
+                        else
+                                size = 0;
+                }
         }
 
         vma->vm_ops = &videobuf_vm_ops;