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dma-debug: remove broken dma memory leak detection for 2.6.30

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The feature needs some more work because the notfier which is used to
check for pending allocations is called before the device drivers
->remove() function. Therefore this feature reports false positives.

A real fix for this issue is to introduce a new notifier event which sent
_after_ the driver has deinitialized itself. That will done for the next
kernel version.

[ Impact: reduce the scope of CONFIG_DMA_API_DEBUG=y checks ]

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Cc: iommu@lists.linux-foundation.org
LKML-Reference: <1240576557-22442-1-git-send-email-joerg.roedel@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Joerg Roedel 2009-04-24 14:35:57 +02:00 committed by Ingo Molnar
parent 992d7ced75
commit 314eeac9e3
1 changed files with 1 additions and 52 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

53
lib/dma-debug.c
View file

@ -400,60 +400,9 @@ static int dma_debug_fs_init(void)
return -ENOMEM;
}
static int device_dma_allocations(struct device *dev)
{
struct dma_debug_entry *entry;
unsigned long flags;
int count = 0, i;
for (i = 0; i < HASH_SIZE; ++i) {
spin_lock_irqsave(&dma_entry_hash[i].lock, flags);
list_for_each_entry(entry, &dma_entry_hash[i].list, list) {
if (entry->dev == dev)
count += 1;
}
spin_unlock_irqrestore(&dma_entry_hash[i].lock, flags);
}
return count;
}
static int dma_debug_device_change(struct notifier_block *nb,
unsigned long action, void *data)
{
struct device *dev = data;
int count;
switch (action) {
case BUS_NOTIFY_UNBIND_DRIVER:
count = device_dma_allocations(dev);
if (count == 0)
break;
err_printk(dev, NULL, "DMA-API: device driver has pending "
"DMA allocations while released from device "
"[count=%d]\n", count);
break;
default:
break;
}
return 0;
}
void dma_debug_add_bus(struct bus_type *bus)
{
struct notifier_block *nb;
nb = kzalloc(sizeof(struct notifier_block), GFP_KERNEL);
if (nb == NULL) {
printk(KERN_ERR "dma_debug_add_bus: out of memory\n");
return;
}
nb->notifier_call = dma_debug_device_change;
bus_register_notifier(bus, nb);
/* FIXME: register notifier */
}
/*