From: Stephen Barber <smbarber@chromium.org>
Date: Tue, 1 Nov 2016 23:44:27 +0000 (-0700)
Subject: dmaengine: pl330: Handle xferred count if DMAMOV hasn't finished
X-Git-Tag: v5.15~12265^2~37
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=c44da03dd517c11c2b3525937b0a241fc1c69399;p=platform%2Fkernel%2Flinux-starfive.git

dmaengine: pl330: Handle xferred count if DMAMOV hasn't finished

After executing DMAGO it's possible that a request can come in for the
current xferred count, but if that happens too soon then DMAMOV SAR/DAR
may not have yet completed. If that happens, we should explicitly return 0
since nothing has been transferred yet.

Signed-off-by: Stephen Barber <smbarber@chromium.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
---

diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
index 030fe05..458a712 100644
--- a/drivers/dma/pl330.c
+++ b/drivers/dma/pl330.c
@@ -2263,6 +2263,11 @@ static int pl330_get_current_xferred_count(struct dma_pl330_chan *pch,
 	}
 	pm_runtime_mark_last_busy(pch->dmac->ddma.dev);
 	pm_runtime_put_autosuspend(pl330->ddma.dev);
+
+	/* If DMAMOV hasn't finished yet, SAR/DAR can be zero */
+	if (!val)
+		return 0;
+
 	return val - addr;
 }