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authorSteven J. Magnani <steve@digidescorp.com>2010-02-28 22:18:16 -0700
committerDan Williams <dan.j.williams@intel.com>2010-02-28 22:18:16 -0700
commit76bd061f5c7b7550cdaed68ad6219ea7cee288fc (patch)
tree5ae663b8bab6bd77cab2b8bc095c0743cc2da138
parent6ca3a7a96e91b1aa8c704153c992b191d35b5747 (diff)
fsldma: Fix cookie issues
fsl_dma_update_completed_cookie() appears to calculate the last completed cookie incorrectly in the corner case where DMA on cookie 1 is in progress just following a cookie wrap. Signed-off-by: Steven J. Magnani <steve@digidescorp.com> Acked-by: Ira W. Snyder <iws@ovro.caltech.edu> [dan.j.williams@intel.com: fix an integer overflow warning with INT_MAX] Signed-off-by: Dan Williams <dan.j.williams@intel.com>
-rw-r--r--drivers/dma/fsldma.c5
-rw-r--r--include/linux/dmaengine.h2
2 files changed, 6 insertions, 1 deletions
diff --git a/drivers/dma/fsldma.c b/drivers/dma/fsldma.c
index 6541ebf8bf6..bbb4be5a3ff 100644
--- a/drivers/dma/fsldma.c
+++ b/drivers/dma/fsldma.c
@@ -819,8 +819,11 @@ static void fsl_dma_update_completed_cookie(struct fsldma_chan *chan)
desc = to_fsl_desc(chan->ld_running.prev);
if (dma_is_idle(chan))
cookie = desc->async_tx.cookie;
- else
+ else {
cookie = desc->async_tx.cookie - 1;
+ if (unlikely(cookie < DMA_MIN_COOKIE))
+ cookie = DMA_MAX_COOKIE;
+ }
chan->completed_cookie = cookie;
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index 78784982b33..4d8d619f28b 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -31,6 +31,8 @@
* if dma_cookie_t is >0 it's a DMA request cookie, <0 it's an error code
*/
typedef s32 dma_cookie_t;
+#define DMA_MIN_COOKIE 1
+#define DMA_MAX_COOKIE INT_MAX
#define dma_submit_error(cookie) ((cookie) < 0 ? 1 : 0)