From 76bd061f5c7b7550cdaed68ad6219ea7cee288fc Mon Sep 17 00:00:00 2001 From: "Steven J. Magnani" Date: Sun, 28 Feb 2010 22:18:16 -0700 Subject: [PATCH] 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 Acked-by: Ira W. Snyder [dan.j.williams@intel.com: fix an integer overflow warning with INT_MAX] Signed-off-by: Dan Williams --- drivers/dma/fsldma.c | 5 ++++- include/linux/dmaengine.h | 2 ++ 2 files changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/dma/fsldma.c b/drivers/dma/fsldma.c index 6541ebf..bbb4be5 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 7878498..4d8d619 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) -- 2.7.4