| Message ID | 1266860439-17352-1-git-send-email-steve@digidescorp.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Kumar Gala |
| Headers | show |
On Mon, Feb 22, 2010 at 09:26:13PM +0100, Guennadi Liakhovetski wrote: > On Mon, 22 Feb 2010, Steven J. Magnani wrote: > > > 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 2147483647 > > Taking into account, that dma_cookie_t is 32 bits: > > +#define DMA_MAX_COOKIE ((1 << 31) - 1) > Steven, After you take Guennadi's comment into acount, the rest of the patch looks good. I'm sure I've never rolled the cookie around during testing. Ira
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 2147483647 #define dma_submit_error(cookie) ((cookie) < 0 ? 1 : 0)
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> ---