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 <[email protected]>
---
diff -uprN a/drivers/dma/fsldma.c b/drivers/dma/fsldma.c
--- a/drivers/dma/fsldma.c 2010-02-22 11:16:36.000000000 -0600
+++ b/drivers/dma/fsldma.c 2010-02-22 11:08:41.000000000 -0600
@@ -819,8 +819,11 @@ static void fsl_dma_update_completed_coo
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 -uprN a/include/linux/dmaengine.h b/include/linux/dmaengine.h
--- a/include/linux/dmaengine.h 2010-02-22 11:18:11.000000000 -0600
+++ b/include/linux/dmaengine.h 2010-02-22 11:18:30.000000000 -0600
@@ -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 ((1 << 31) - 1)
#define dma_submit_error(cookie) ((cookie) < 0 ? 1 : 0)