[PATCH v2 1/2] dmaengine: dw: fix cyclic transfer setup

From: Mans Rullgard
Date: Mon Jan 11 2016 - 08:04:42 EST


Commit 61e183f83069 ("dmaengine/dw_dmac: Reconfigure interrupt and
chan_cfg register on resume") moved some channel initialisation to
a new function which must be called before starting a transfer.

This updates dw_dma_cyclic_start() to use dwc_dostart() like the other
modes, thus ensuring dwc_initialize() gets called and removing some code
duplication.

Fixes: 61e183f83069 ("dmaengine/dw_dmac: Reconfigure interrupt and chan_cfg register on resume")
Signed-off-by: Mans Rullgard <mans@xxxxxxxxx>
---
Changes:
- replace duplicated code by dwc_dostart() call
---
drivers/dma/dw/core.c | 23 +----------------------
1 file changed, 1 insertion(+), 22 deletions(-)

diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c
index 7067b6ddc1db..af2b92f8501e 100644
--- a/drivers/dma/dw/core.c
+++ b/drivers/dma/dw/core.c
@@ -1245,7 +1245,6 @@ static void dwc_free_chan_resources(struct dma_chan *chan)
int dw_dma_cyclic_start(struct dma_chan *chan)
{
struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
- struct dw_dma *dw = to_dw_dma(dwc->chan.device);
unsigned long flags;

if (!test_bit(DW_DMA_IS_CYCLIC, &dwc->flags)) {
@@ -1254,27 +1253,7 @@ int dw_dma_cyclic_start(struct dma_chan *chan)
}

spin_lock_irqsave(&dwc->lock, flags);
-
- /* Assert channel is idle */
- if (dma_readl(dw, CH_EN) & dwc->mask) {
- dev_err(chan2dev(&dwc->chan),
- "%s: BUG: Attempted to start non-idle channel\n",
- __func__);
- dwc_dump_chan_regs(dwc);
- spin_unlock_irqrestore(&dwc->lock, flags);
- return -EBUSY;
- }
-
- dma_writel(dw, CLEAR.ERROR, dwc->mask);
- dma_writel(dw, CLEAR.XFER, dwc->mask);
-
- /* Setup DMAC channel registers */
- channel_writel(dwc, LLP, dwc->cdesc->desc[0]->txd.phys);
- channel_writel(dwc, CTL_LO, DWC_CTLL_LLP_D_EN | DWC_CTLL_LLP_S_EN);
- channel_writel(dwc, CTL_HI, 0);
-
- channel_set_bit(dw, CH_EN, dwc->mask);
-
+ dwc_dostart(dwc, dwc->cdesc->desc[0]);
spin_unlock_irqrestore(&dwc->lock, flags);

return 0;
--
2.7.0