Date: Tue, 25 Mar 2008 16:47:16 -0400 From: Jarod Wilson Subject: firewire: fw-ohci: plug dma memory leak in AR handler There's an ugly little memory leak in firewire-ohci's ar_context_tasklet(), where we're not freeing up some of the memory we use for each ar_buffer, due to a moving pointer. The problem has been there for a while, but didn't get noticed until after converting the AR routines over to use coherent DMA and I started running into I/O stall- outs with the following message output repeatedly to the console: PCI-DMA: Out of IOMMU space for 53248 bytes at device 0000:04:09.0 Plugging this leak is definitely necessary, but unfortunately, isn't the entire answer to my problem, it only increases the amount of I/O that I can do before hitting the problem. Still working on tracking down the root cause.. Signed-off-by: Jarod Wilson Signed-off-by: Stefan Richter --- drivers/firewire/fw-ohci.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) Index: linux/drivers/firewire/fw-ohci.c =================================================================== --- linux.orig/drivers/firewire/fw-ohci.c +++ linux/drivers/firewire/fw-ohci.c @@ -401,7 +401,8 @@ static void ar_context_tasklet(unsigned if (d->res_count == 0) { size_t size, rest, offset; - dma_addr_t buffer_bus; + dma_addr_t start_bus; + void *start; /* * This descriptor is finished and we may have a @@ -410,9 +411,9 @@ static void ar_context_tasklet(unsigned */ offset = offsetof(struct ar_buffer, data); - buffer_bus = le32_to_cpu(ab->descriptor.data_address) - offset; + start = buffer = ab; + start_bus = le32_to_cpu(ab->descriptor.data_address) - offset; - buffer = ab; ab = ab->next; d = &ab->descriptor; size = buffer + PAGE_SIZE - ctx->pointer; @@ -427,7 +428,7 @@ static void ar_context_tasklet(unsigned buffer = handle_ar_packet(ctx, buffer); dma_free_coherent(ohci->card.device, PAGE_SIZE, - buffer, buffer_bus); + start, start_bus); ar_context_add_page(ctx); } else { buffer = ctx->pointer;