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dw_dmac: remove unnecessary tx_list field in dw_dma_chan 

The soft LLP mode is working for active descriptor only. So, we do not need to
have a copy of its pointer.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
This commit is contained in:
Andy Shevchenko 2013-01-25 11:48:00 +02:00 committed by Vinod Koul
parent 985a6c7dcf
commit fdf475fa40
2 changed files with 15 additions and 6 deletions
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20
drivers/dma/dw_dmac.c
View File

@ -282,9 +282,9 @@ static void dwc_dostart(struct dw_dma_chan *dwc, struct dw_desc *first)
dwc_initialize(dwc);
dwc->tx_list = &first->tx_list;
dwc->tx_node_active = &first->tx_list;
/* Submit first block */
dwc_do_single_block(dwc, first);
return;
@ -402,15 +402,25 @@ static void dwc_scan_descriptors(struct dw_dma *dw, struct dw_dma_chan *dwc)
dma_writel(dw, CLEAR.XFER, dwc->mask);
if (test_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags)) {
if (dwc->tx_node_active != dwc->tx_list) {
desc = to_dw_desc(dwc->tx_node_active);
struct list_head *head, *active = dwc->tx_node_active;
/*
* We are inside first active descriptor.
* Otherwise something is really wrong.
*/
desc = dwc_first_active(dwc);
head = &desc->tx_list;
if (active != head) {
child = to_dw_desc(active);
/* Submit next block */
dwc_do_single_block(dwc, desc);
spin_unlock_irqrestore(&dwc->lock, flags);
dwc_do_single_block(dwc, child);
spin_unlock_irqrestore(&dwc->lock, flags);
return;
}
/* We are done here */
clear_bit(DW_DMA_IS_SOFT_LLP, &dwc->flags);
}

1
drivers/dma/dw_dmac_regs.h
View File

@ -194,7 +194,6 @@ struct dw_dma_chan {
bool initialized;
/* software emulation of the LLP transfers */
struct list_head *tx_list;
struct list_head *tx_node_active;
spinlock_t lock;