Date: Wed, 12 Mar 2008 17:43:26 -0400 From: Jarod Wilson Subject: firewire: fw-ohci: use dma_alloc_coherent for ar_buffer Currently, we do nothing to guarantee we have a consistent DMA buffer for asynchronous receive packets. Rather than doing several sync's following a dma_map_single() to get consistent buffers, just switch to using dma_alloc_coherent(). Resolves constant buffer failures on my own x86_64 laptop w/4GB of RAM and likely to fix a number of other failures witnessed on x86_64 systems with 4GB of RAM or more. Signed-off-by: Jarod Wilson Signed-off-by: Stefan Richter --- drivers/firewire/fw-ohci.c | 18 +++++------------- 1 file changed, 5 insertions(+), 13 deletions(-) Index: linux/drivers/firewire/fw-ohci.c =================================================================== --- linux.orig/drivers/firewire/fw-ohci.c +++ linux/drivers/firewire/fw-ohci.c @@ -284,16 +284,10 @@ static int ar_context_add_page(struct ar dma_addr_t ab_bus; size_t offset; - ab = (struct ar_buffer *) __get_free_page(GFP_ATOMIC); + ab = dma_alloc_coherent(dev, PAGE_SIZE, &ab_bus, GFP_ATOMIC); if (ab == NULL) return -ENOMEM; - ab_bus = dma_map_single(dev, ab, PAGE_SIZE, DMA_BIDIRECTIONAL); - if (dma_mapping_error(ab_bus)) { - free_page((unsigned long) ab); - return -ENOMEM; - } - memset(&ab->descriptor, 0, sizeof(ab->descriptor)); ab->descriptor.control = cpu_to_le16(DESCRIPTOR_INPUT_MORE | DESCRIPTOR_STATUS | @@ -304,8 +298,6 @@ static int ar_context_add_page(struct ar ab->descriptor.res_count = cpu_to_le16(PAGE_SIZE - offset); ab->descriptor.branch_address = 0; - dma_sync_single_for_device(dev, ab_bus, PAGE_SIZE, DMA_BIDIRECTIONAL); - ctx->last_buffer->descriptor.branch_address = cpu_to_le32(ab_bus | 1); ctx->last_buffer->next = ab; ctx->last_buffer = ab; @@ -409,6 +401,7 @@ static void ar_context_tasklet(unsigned if (d->res_count == 0) { size_t size, rest, offset; + dma_addr_t buffer_bus; /* * This descriptor is finished and we may have a @@ -417,9 +410,7 @@ static void ar_context_tasklet(unsigned */ offset = offsetof(struct ar_buffer, data); - dma_unmap_single(ohci->card.device, - le32_to_cpu(ab->descriptor.data_address) - offset, - PAGE_SIZE, DMA_BIDIRECTIONAL); + buffer_bus = le32_to_cpu(ab->descriptor.data_address) - offset; buffer = ab; ab = ab->next; @@ -435,7 +426,8 @@ static void ar_context_tasklet(unsigned while (buffer < end) buffer = handle_ar_packet(ctx, buffer); - free_page((unsigned long)buffer); + dma_free_coherent(ohci->card.device, PAGE_SIZE, + buffer, buffer_bus); ar_context_add_page(ctx); } else { buffer = ctx->pointer;