Messages in this thread Patch in this message | | | Date | Tue, 16 Oct 2007 19:58:46 +0200 (CEST) | From | Stefan Richter <> | Subject | [PATCH] firewire: fw-ohci: optimize initialization of ar context |
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Sync only the parts for CPU which are actually accessed by the CPU. Replace a memset by direct assignment.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> --- drivers/firewire/fw-ohci.c | 22 ++++++++++++---------- 1 file changed, 12 insertions(+), 10 deletions(-)
Index: linux/drivers/firewire/fw-ohci.c =================================================================== --- linux.orig/drivers/firewire/fw-ohci.c +++ linux/drivers/firewire/fw-ohci.c @@ -258,19 +258,21 @@ static int ar_context_add_page(struct ar free_page((unsigned long) ab); return -ENOMEM; } - dma_sync_single_for_cpu(dev, ab_bus, PAGE_SIZE, DMA_BIDIRECTIONAL); + dma_sync_single_for_cpu(dev, ab_bus, sizeof(ab->descriptor), + DMA_BIDIRECTIONAL); - memset(&ab->descriptor, 0, sizeof(ab->descriptor)); - ab->descriptor.control = cpu_to_le16(DESCRIPTOR_INPUT_MORE | - DESCRIPTOR_STATUS | - DESCRIPTOR_BRANCH_ALWAYS); offset = offsetof(struct ar_buffer, data); - ab->descriptor.req_count = cpu_to_le16(PAGE_SIZE - offset); - ab->descriptor.data_address = cpu_to_le32(ab_bus + offset); - ab->descriptor.res_count = cpu_to_le16(PAGE_SIZE - offset); - ab->descriptor.branch_address = 0; + ab->descriptor.req_count = cpu_to_le16(PAGE_SIZE - offset); + ab->descriptor.control = cpu_to_le16(DESCRIPTOR_INPUT_MORE | + DESCRIPTOR_STATUS | + DESCRIPTOR_BRANCH_ALWAYS); + ab->descriptor.data_address = cpu_to_le32(ab_bus + offset); + ab->descriptor.branch_address = 0; + ab->descriptor.res_count = cpu_to_le16(PAGE_SIZE - offset); + ab->descriptor.transfer_status = 0; - dma_sync_single_for_device(dev, ab_bus, PAGE_SIZE, DMA_BIDIRECTIONAL); + dma_sync_single_for_device(dev, ab_bus, sizeof(ab->descriptor), + DMA_BIDIRECTIONAL); ctx->last_buffer->descriptor.branch_address = cpu_to_le32(ab_bus | 1); ctx->last_buffer->next = ab; -- Stefan Richter -=====-=-=== =-=- =---- http://arcgraph.de/sr/ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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