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Message-Id: <1453926929-17663-124-git-send-email-kamal@canonical.com>
Date: Wed, 27 Jan 2016 12:33:04 -0800
From: Kamal Mostafa <kamal@...onical.com>
To: linux-kernel@...r.kernel.org, stable@...r.kernel.org,
kernel-team@...ts.ubuntu.com
Cc: Mans Rullgard <mans@...sr.com>, Vinod Koul <vinod.koul@...el.com>,
Kamal Mostafa <kamal@...onical.com>
Subject: [PATCH 4.2.y-ckt 123/268] dmaengine: dw: fix cyclic transfer setup
4.2.8-ckt3 -stable review patch. If anyone has any objections, please let me know.
---8<------------------------------------------------------------
From: Mans Rullgard <mans@...sr.com>
commit df3bb8a0e619d501cd13334c3e0586edcdcbc716 upstream.
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@...sr.com>
Reviewed-by: Viresh Kumar <viresh.kumar@...aro.org>
Signed-off-by: Vinod Koul <vinod.koul@...el.com>
Signed-off-by: Kamal Mostafa <kamal@...onical.com>
---
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 4287c7c..70d3b21 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;
--
1.9.1
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