On Mon, Dec 17, 2018 at 02:27:47PM +0100, Geert Uytterhoeven wrote: > Hi Simon, > > On Mon, Dec 17, 2018 at 2:22 PM Simon Horman <horms@xxxxxxxxxxxx> wrote: > > On Thu, Dec 13, 2018 at 07:44:42PM +0100, Geert Uytterhoeven wrote: > > > When falling back to PIO, active_rx must be set to a different value > > > than cookie_rx[i], else sci_dma_rx_find_active() will incorrectly find a > > > match, leading to a NULL pointer dereference in rx_timer_fn() later. > > > > > > Use zero instead, which is the same value as after driver > > > initialization. > > > > > > Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx> > > > > This looks good so to me long as dmaengine_submit() doesn't return 0. > > Is that the case? > > include/linux/dmaengine.h: > > /** > * typedef dma_cookie_t - an opaque DMA cookie > * > * 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 In that case I have no objections. Reviewed-by: Simon Horman <horms+renesas@xxxxxxxxxxxx>
