1 files changed, 21 insertions, 14 deletions

diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c
index 5826ae333b19..7570b71a2453 100644
--- a/drivers/firewire/ohci.c
+++ b/drivers/firewire/ohci.c
@@ -750,20 +750,19 @@ static void ar_context_tasklet(unsigned long data)
 		 */
 
 		offset = offsetof(struct ar_buffer, data);
-		start = buffer = ab;
+		start = ab;
 		start_bus = le32_to_cpu(ab->descriptor.data_address) - offset;
+		buffer = ab->data;
 
 		ab = ab->next;
 		d = &ab->descriptor;
-		size = buffer + PAGE_SIZE - ctx->pointer;
+		size = start + PAGE_SIZE - ctx->pointer;
 		/* valid buffer data in the next page */
 		rest = le16_to_cpu(d->req_count) - le16_to_cpu(d->res_count);
 		/* what actually fits in this page */
-		size2 = min(rest, (size_t)PAGE_SIZE - size);
+		size2 = min(rest, (size_t)PAGE_SIZE - offset - size);
 		memmove(buffer, ctx->pointer, size);
 		memcpy(buffer + size, ab->data, size2);
-		ctx->current_buffer = ab;
-		ctx->pointer = (void *) ab->data + rest;
 
 		while (size > 0) {
 			void *next = handle_ar_packet(ctx, buffer);
@@ -782,22 +781,30 @@ static void ar_context_tasklet(unsigned long data)
 			size -= pktsize;
 			/* fill up this page again */
 			size3 = min(rest - size2,
-				    (size_t)PAGE_SIZE - size - size2);
+				    (size_t)PAGE_SIZE - offset - size - size2);
 			memcpy(buffer + size + size2,
 			       (void *) ab->data + size2, size3);
 			size2 += size3;
 		}
 
-		/* handle the packets that are fully in the next page */
-		buffer = (void *) ab->data + (buffer - (start + size));
-		end = (void *) ab->data + rest;
+		if (rest > 0) {
+			/* handle the packets that are fully in the next page */
+			buffer = (void *) ab->data +
+					(buffer - (start + offset + size));
+			end = (void *) ab->data + rest;
 
-		while (buffer < end)
-			buffer = handle_ar_packet(ctx, buffer);
+			while (buffer < end)
+				buffer = handle_ar_packet(ctx, buffer);
+
+			ctx->current_buffer = ab;
+			ctx->pointer = end;
 
-		dma_free_coherent(ohci->card.device, PAGE_SIZE,
-				  start, start_bus);
-		ar_context_add_page(ctx);
+			dma_free_coherent(ohci->card.device, PAGE_SIZE,
+					  start, start_bus);
+			ar_context_add_page(ctx);
+		} else {
+			ctx->pointer = start + PAGE_SIZE;
+		}
 	} else {
 		buffer = ctx->pointer;
 		ctx->pointer = end =