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dmaengine: dw: properly read DWC_PARAMS register 

In case we have less than maximum allowed channels (8) and autoconfiguration is
enabled the DWC_PARAMS read is wrong because it uses different arithmetic to
what is needed for channel priority setup.

Re-do the caclulations properly. This now works on AVR32 board well.

Fixes: fed2574b3c (dw_dmac: introduce software emulation of LLP transfers)
Cc: yitian.bu@tangramtek.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
This commit is contained in:
Andy Shevchenko 2015-09-28 18:57:03 +03:00 committed by Vinod Koul
parent ee08b59d47
commit 6bea0f6d1c
1 changed files with 2 additions and 2 deletions
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4
drivers/dma/dw/core.c
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@ -1591,7 +1591,6 @@ int dw_dma_probe(struct dw_dma_chip *chip, struct dw_dma_platform_data *pdata)
INIT_LIST_HEAD(&dw->dma.channels);
for (i = 0; i < nr_channels; i++) {
struct dw_dma_chan *dwc = &dw->chan[i];
int r = nr_channels - i - 1;
dwc->chan.device = &dw->dma;
dma_cookie_init(&dwc->chan);
@ -1603,7 +1602,7 @@ int dw_dma_probe(struct dw_dma_chip *chip, struct dw_dma_platform_data *pdata)
/* 7 is highest priority & 0 is lowest. */
if (pdata->chan_priority == CHAN_PRIORITY_ASCENDING)
dwc->priority = r;
dwc->priority = nr_channels - i - 1;
else
dwc->priority = i;
@ -1622,6 +1621,7 @@ int dw_dma_probe(struct dw_dma_chip *chip, struct dw_dma_platform_data *pdata)
/* Hardware configuration */
if (autocfg) {
unsigned int dwc_params;
unsigned int r = DW_DMA_MAX_NR_CHANNELS - i - 1;
void __iomem *addr = chip->regs + r * sizeof(u32);
dwc_params = dma_read_byaddr(addr, DWC_PARAMS);