dma: coh901318: set residue only if dma is in progress

When status is DMA_SUCCESS the residue should be zero. Otherwise it's a bug.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

drivers/dma/coh901318.c

@@ -1147,7 +1147,9 @@ coh901318_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
 	enum dma_status ret;
 
 	ret = dma_cookie_status(chan, cookie, txstate);
-	/* FIXME: should be conditional on ret != DMA_SUCCESS? */
+	if (ret == DMA_SUCCESS)
+		return ret;
+
 	dma_set_residue(txstate, coh901318_get_bytes_left(chan));
 
 	if (ret == DMA_IN_PROGRESS && cohc->stopped)