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 <jwilson@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
diff --git a/drivers/firewire/fw-ohci.c b/drivers/firewire/fw-ohci.c
index 996d61f..ca6d51e 100644
--- a/drivers/firewire/fw-ohci.c
+++ b/drivers/firewire/fw-ohci.c
@@ -401,7 +401,8 @@
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 @@
*/
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 @@
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;