From: Kuninori Morimoto <kuninori.morimoto.gx@xxxxxxxxxxx>
We need to clear channel register in error case as recovery.
The channel is already stopped in such case, thus we don't need to call
rcar_dmac_chan_halt() before clearing.
rcar_dmac_chan_halt() will clear register and confirm DE bit.
But it will be failed because channel is already stopped in error case.
In other words, we shouldn't call it then.
// This patch started to use C++ style comment out
// because it is recent Linus request
Reported-by: Hiroki Negishi <hiroki.negishi.bx@xxxxxxxxxxx>
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@xxxxxxxxxxx>
Reviewed-by: Hiroki Negishi <hiroki.negishi.bx@xxxxxxxxxxx>
---
drivers/dma/sh/rcar-dmac.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/drivers/dma/sh/rcar-dmac.c b/drivers/dma/sh/rcar-dmac.c
index 279c930..35d7a16 100644
--- a/drivers/dma/sh/rcar-dmac.c
+++ b/drivers/dma/sh/rcar-dmac.c
@@ -1525,7 +1525,13 @@ static irqreturn_t rcar_dmac_isr_channel(int irq, void *dev)
chcr = rcar_dmac_chan_read(chan, RCAR_DMACHCR);
if (chcr & RCAR_DMACHCR_CAE) {
- rcar_dmac_chan_halt(chan);
+ struct rcar_dmac *dmac = dev_get_drvdata(chan->chan.device->dev);
+
+ // We don't need to call rcar_dmac_chan_halt()
+ // because channel is already stopped in error case.
+ // We need to clear register and check DE bit as recovery.
+ rcar_dmac_write(dmac, RCAR_DMACHCLR, 1 << chan->index);
+ rcar_dmac_chcr_de_barrier(chan);
reinit = true;
goto spin_lock_end;
}
--
2.7.4
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