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, 8 deletions

diff --git a/drivers/firewire/fw-ohci.c b/drivers/firewire/fw-ohci.c
index e6fa3496183e..4512edba6cb0 100644
--- a/drivers/firewire/fw-ohci.c
+++ b/drivers/firewire/fw-ohci.c
@@ -431,7 +431,7 @@ at_context_setup_packet(struct at_context *ctx, struct list_head *list)
                                                      packet->payload,
                                                      packet->payload_length,
                                                      DMA_TO_DEVICE);
-                if (packet->payload_bus == 0) {
+                if (dma_mapping_error(packet->payload_bus)) {
                         complete_transmission(packet, RCODE_SEND_ERROR, list);
                         return;
                 }
@@ -590,7 +590,7 @@ at_context_init(struct at_context *ctx, struct fw_ohci *ohci, u32 regs)
         ctx->descriptor_bus =
                 dma_map_single(ohci->card.device, &ctx->d,
                                sizeof ctx->d, DMA_TO_DEVICE);
-        if (ctx->descriptor_bus == 0)
+        if (dma_mapping_error(ctx->descriptor_bus))
                 return -ENOMEM;
 
         ctx->regs = regs;
@@ -1159,16 +1159,14 @@ static struct fw_iso_context *ohci_allocate_iso_context(struct fw_card *card,
         tasklet_init(&ctx->tasklet, tasklet, (unsigned long)ctx);
 
         ctx->buffer = kmalloc(ISO_BUFFER_SIZE, GFP_KERNEL);
-        if (ctx->buffer == NULL) {
-                spin_lock_irqsave(&ohci->lock, flags);
-                *mask |= 1 << index;
-                spin_unlock_irqrestore(&ohci->lock, flags);
-                return ERR_PTR(-ENOMEM);
-        }
+        if (ctx->buffer == NULL)
+                goto buffer_alloc_failed;
 
         ctx->buffer_bus =
             dma_map_single(card->device, ctx->buffer,
                            ISO_BUFFER_SIZE, DMA_TO_DEVICE);
+        if (dma_mapping_error(ctx->buffer_bus))
+                goto buffer_map_failed;
 
         ctx->head_descriptor      = ctx->buffer;
         ctx->prev_descriptor      = ctx->buffer;
@@ -1187,6 +1185,15 @@ static struct fw_iso_context *ohci_allocate_iso_context(struct fw_card *card,
         ctx->head_descriptor++;
 
         return &ctx->base;
+
+ buffer_map_failed:
+        kfree(ctx->buffer);
+ buffer_alloc_failed:
+        spin_lock_irqsave(&ohci->lock, flags);
+        *mask |= 1 << index;
+        spin_unlock_irqrestore(&ohci->lock, flags);
+
+        return ERR_PTR(-ENOMEM);
 }
 
 static int ohci_send_iso(struct fw_iso_context *base, s32 cycle)