From: Kuninori Morimoto <[email protected]>
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 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. Reported-by: Hiroki Negishi <[email protected]> Signed-off-by: Kuninori Morimoto <[email protected]> Reviewed-by: Hiroki Negishi <[email protected]> --- v1 -> v2 - use /* */ style comment instead of C++ style - Cc:ed to Negishi-san drivers/dma/sh/rcar-dmac.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/dma/sh/rcar-dmac.c b/drivers/dma/sh/rcar-dmac.c index 279c930..a65292d 100644 --- a/drivers/dma/sh/rcar-dmac.c +++ b/drivers/dma/sh/rcar-dmac.c @@ -1525,7 +1525,15 @@ 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
