[patch 24/49] I/OAT: fix channel resources free for not allocated channels

Greg KH
2008-11-12T00:35:22Z

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2.6.27-stable review patch. If anyone has any objections, please let us know.

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From: Maciej Sosnowski <maciej.sosnowski@intel.com>

commit c3d4f44f50b65b0b0290e357f8739cfb3f4bcaca upstream

If the ioatdma driver is loaded but not used it does not allocate descriptors.
Before it frees channel resources it should first be sure
that they have been previously allocated.

Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Tested-by: Tom Picard <tom.s.picard@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
drivers/dma/ioat_dma.c | 7 +++++++
1 file changed, 7 insertions(+)

--- a/drivers/dma/ioat_dma.c
+++ b/drivers/dma/ioat_dma.c
@@ -801,6 +801,12 @@ static void ioat_dma_free_chan_resources
struct ioat_desc_sw *desc, *_desc;
int in_use_descs = 0;

+ /* Before freeing channel resources first check
+ * if they have been previously allocated for this channel.
+ */
+ if (ioat_chan->desccount == 0)
+ return;
+
tasklet_disable(&ioat_chan->cleanup_task);
ioat_dma_memcpy_cleanup(ioat_chan);

@@ -863,6 +869,7 @@ static void ioat_dma_free_chan_resources
ioat_chan->last_completion = ioat_chan->completion_addr = 0;
ioat_chan->pending = 0;
ioat_chan->dmacount = 0;
+ ioat_chan->desccount = 0;
ioat_chan->watchdog_completion = 0;
ioat_chan->last_compl_desc_addr_hw = 0;
ioat_chan->watchdog_tcp_cookie =

--