1 files changed, 4 insertions, 2 deletions

diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c
index b5ba66656c6c..84eb607d6c03 100644
--- a/drivers/firewire/ohci.c
+++ b/drivers/firewire/ohci.c
@@ -740,11 +740,13 @@ static void ar_context_tasklet(unsigned long data)
         struct ar_buffer *ab;
         struct descriptor *d;
         void *buffer, *end;
+        __le16 res_count;
 
         ab = ctx->current_buffer;
         d = &ab->descriptor;
 
-        if (d->res_count == 0) {
+        res_count = ACCESS_ONCE(d->res_count);
+        if (res_count == 0) {
                 size_t size, size2, rest, pktsize, size3, offset;
                 dma_addr_t start_bus;
                 void *start;
@@ -812,7 +814,7 @@ static void ar_context_tasklet(unsigned long data)
         } else {
                 buffer = ctx->pointer;
                 ctx->pointer = end =
-                        (void *) ab + PAGE_SIZE - le16_to_cpu(d->res_count);
+                        (void *) ab + PAGE_SIZE - le16_to_cpu(res_count);
 
                 while (buffer < end)
                         buffer = handle_ar_packet(ctx, buffer);