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| author | Andy Shevchenko <andriy.shevchenko@linux.intel.com> | 2020-07-05 14:56:20 +0300 |
|---|---|---|
| committer | Vinod Koul <vkoul@kernel.org> | 2020-07-06 10:21:05 +0530 |
| commit | 99ba8b9b0d9780e9937eb1d488d120e9e5c2533d (patch) | |
| tree | 1a5f69b6e0cf89684386d41f83d0bbc2104e4ec7 /drivers/dma | |
| parent | e3122822a74033ba8d6d9af855078f9ab741e33f (diff) | |
| download | linux-99ba8b9b0d9780e9937eb1d488d120e9e5c2533d.tar.gz | |
dmaengine: dw: Initialize channel before each transfer
In some cases DMA can be used only with a consumer which does runtime power
management and on the platforms, that have DMA auto power gating logic
(see comments in the drivers/acpi/acpi_lpss.c), may result in DMA losing
its context. Simple mitigation of this issue is to initialize channel
each time the consumer initiates a transfer.
Fixes: cfdf5b6cc598 ("dw_dmac: add support for Lynxpoint DMA controllers")
Reported-by: Tsuchiya Yuto <kitakar@gmail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=206403
Link: https://lore.kernel.org/r/20200705115620.51929-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'drivers/dma')
| -rw-r--r-- | drivers/dma/dw/core.c | 12 |
1 files changed, 0 insertions, 12 deletions
diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c index 21cb2a58dbd2..a1b56f52db2f 100644 --- a/drivers/dma/dw/core.c +++ b/drivers/dma/dw/core.c @@ -118,16 +118,11 @@ static void dwc_initialize(struct dw_dma_chan *dwc) { struct dw_dma *dw = to_dw_dma(dwc->chan.device); - if (test_bit(DW_DMA_IS_INITIALIZED, &dwc->flags)) - return; - dw->initialize_chan(dwc); /* Enable interrupts */ channel_set_bit(dw, MASK.XFER, dwc->mask); channel_set_bit(dw, MASK.ERROR, dwc->mask); - - set_bit(DW_DMA_IS_INITIALIZED, &dwc->flags); } /*----------------------------------------------------------------------*/ @@ -954,8 +949,6 @@ static void dwc_issue_pending(struct dma_chan *chan) void do_dw_dma_off(struct dw_dma *dw) { - unsigned int i; - dma_writel(dw, CFG, 0); channel_clear_bit(dw, MASK.XFER, dw->all_chan_mask); @@ -966,9 +959,6 @@ void do_dw_dma_off(struct dw_dma *dw) while (dma_readl(dw, CFG) & DW_CFG_DMA_EN) cpu_relax(); - - for (i = 0; i < dw->dma.chancnt; i++) - clear_bit(DW_DMA_IS_INITIALIZED, &dw->chan[i].flags); } void do_dw_dma_on(struct dw_dma *dw) @@ -1032,8 +1022,6 @@ static void dwc_free_chan_resources(struct dma_chan *chan) /* Clear custom channel configuration */ memset(&dwc->dws, 0, sizeof(struct dw_dma_slave)); - clear_bit(DW_DMA_IS_INITIALIZED, &dwc->flags); - /* Disable interrupts */ channel_clear_bit(dw, MASK.XFER, dwc->mask); channel_clear_bit(dw, MASK.BLOCK, dwc->mask); |