firewire: Use dma_mapping_error() for checking for DMA mapping errors.

Pointed out by Pete Zaitcev.

Signed-off-by: Kristian Høgsberg <krh@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

1 files changed, 15 insertions, 6 deletions

diff --git a/drivers/firewire/fw-iso.c b/drivers/firewire/fw-iso.c
index 024fab4ef998..6481e3df2c93 100644
--- a/drivers/firewire/fw-iso.c
+++ b/drivers/firewire/fw-iso.c
@@ -33,7 +33,7 @@ setup_iso_buffer(struct fw_iso_context *ctx, size_t size,
                  enum dma_data_direction direction)
 {
         struct page *page;
-        int i;
+        int i, j;
         void *p;
 
         ctx->buffer_size = PAGE_ALIGN(size);
@@ -42,24 +42,33 @@ setup_iso_buffer(struct fw_iso_context *ctx, size_t size,
 
         ctx->buffer = vmalloc_32_user(ctx->buffer_size);
         if (ctx->buffer == NULL)
-                return -ENOMEM;
+                goto fail_buffer_alloc;
 
         ctx->page_count = ctx->buffer_size >> PAGE_SHIFT;
         ctx->pages =
             kzalloc(ctx->page_count * sizeof(ctx->pages[0]), GFP_KERNEL);
-        if (ctx->pages == NULL) {
-                vfree(ctx->buffer);
-                return -ENOMEM;
-        }
+        if (ctx->pages == NULL)
+                goto fail_pages_alloc;
 
         p = ctx->buffer;
         for (i = 0; i < ctx->page_count; i++, p += PAGE_SIZE) {
                 page = vmalloc_to_page(p);
                 ctx->pages[i] = dma_map_page(ctx->card->device,
                                              page, 0, PAGE_SIZE, direction);
+                if (dma_mapping_error(ctx->pages[i]))
+                        goto fail_mapping;
         }
 
         return 0;
+
+ fail_mapping:
+        for (j = 0; j < i; j++)
+                dma_unmap_page(ctx->card->device, ctx->pages[j],
+                               PAGE_SIZE, DMA_TO_DEVICE);
+ fail_pages_alloc:
+        vfree(ctx->buffer);
+ fail_buffer_alloc:
+        return -ENOMEM;
 }
 
 static void destroy_iso_buffer(struct fw_iso_context *ctx)