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authorAndy Shevchenko <andriy.shevchenko@linux.intel.com>2016-02-10 15:59:42 +0200
committerVinod Koul <vinod.koul@intel.com>2016-02-15 22:19:32 +0530
commitee1cdcdae59563535485a5f56ee72c894ab7d7ad (patch)
treed6aa9036557e0d5432888038b4b62c7a44e04385 /drivers/dma
parent4ac31d18e4125eb2970e69069a15308cbb8e4486 (diff)
downloadlinux-ee1cdcdae59563535485a5f56ee72c894ab7d7ad.tar.bz2
dmaengine: dw: disable BLOCK IRQs for non-cyclic xfer
The commit 2895b2cad6e7 ("dmaengine: dw: fix cyclic transfer callbacks") re-enabled BLOCK interrupts with regard to make cyclic transfers work. However, this change becomes a regression for non-cyclic transfers as interrupt counters under stress test had been grown enormously (approximately per 4-5 bytes in the UART loop back test). Taking into consideration above enable BLOCK interrupts if and only if channel is programmed to perform cyclic transfer. Fixes: 2895b2cad6e7 ("dmaengine: dw: fix cyclic transfer callbacks") Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Mans Rullgard <mans@mansr.com> Tested-by: Mans Rullgard <mans@mansr.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: <stable@vger.kernel.org> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Diffstat (limited to 'drivers/dma')
-rw-r--r--drivers/dma/dw/core.c15
1 files changed, 10 insertions, 5 deletions
diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c
index e893318560db..5ad0ec1f0e29 100644
--- a/drivers/dma/dw/core.c
+++ b/drivers/dma/dw/core.c
@@ -156,7 +156,6 @@ static void dwc_initialize(struct dw_dma_chan *dwc)
/* Enable interrupts */
channel_set_bit(dw, MASK.XFER, dwc->mask);
- channel_set_bit(dw, MASK.BLOCK, dwc->mask);
channel_set_bit(dw, MASK.ERROR, dwc->mask);
dwc->initialized = true;
@@ -588,6 +587,9 @@ static void dwc_handle_cyclic(struct dw_dma *dw, struct dw_dma_chan *dwc,
spin_unlock_irqrestore(&dwc->lock, flags);
}
+
+ /* Re-enable interrupts */
+ channel_set_bit(dw, MASK.BLOCK, dwc->mask);
}
/* ------------------------------------------------------------------------- */
@@ -618,11 +620,8 @@ static void dw_dma_tasklet(unsigned long data)
dwc_scan_descriptors(dw, dwc);
}
- /*
- * Re-enable interrupts.
- */
+ /* Re-enable interrupts */
channel_set_bit(dw, MASK.XFER, dw->all_chan_mask);
- channel_set_bit(dw, MASK.BLOCK, dw->all_chan_mask);
channel_set_bit(dw, MASK.ERROR, dw->all_chan_mask);
}
@@ -1261,6 +1260,7 @@ 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(chan->device);
unsigned long flags;
if (!test_bit(DW_DMA_IS_CYCLIC, &dwc->flags)) {
@@ -1269,7 +1269,12 @@ int dw_dma_cyclic_start(struct dma_chan *chan)
}
spin_lock_irqsave(&dwc->lock, flags);
+
+ /* Enable interrupts to perform cyclic transfer */
+ channel_set_bit(dw, MASK.BLOCK, dwc->mask);
+
dwc_dostart(dwc, dwc->cdesc->desc[0]);
+
spin_unlock_irqrestore(&dwc->lock, flags);
return 0;