Commit bde1709a authored by Jarod Wilson's avatar Jarod Wilson Committed by Stefan Richter
Browse files

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: default avatarJarod Wilson <jwilson@redhat.com>
Signed-off-by: default avatarStefan Richter <stefanr@s5r6.in-berlin.de>
parent 6e45ef4c

drivers/firewire/fw-ohci.c

+5 −13
Original line number Diff line number Diff line
@@ -284,16 +284,10 @@ static int ar_context_add_page(struct ar_context *ctx) 
	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_context *ctx) 
	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 long data) 


	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 long data) 
		 */



		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 long data) 
		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;

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