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MLK-19451: dmaengine: imx-sdma: remove mdelay(1) 

commit 7f3ff14b7e ("dmaengine: imx-sdma: add 1ms delay to ensure
SDMA channel is stopped") add 1ms delay to ensure no dma done interrupt
come in after channel disabled. This 1ms may cause SAI underrun issue
between two times playback, because ALSA framework stop SAI module after
dma terminate, thus the 1ms timing window trigger continuous 'underrun'
interrupt. Actually, don't need 1ms delay anymore since virt-dma could
handle the interrupt after channel terminated.

Signed-off-by: Robin Gong <yibin.gong@nxp.com>
Reviewed-by: Shengjiu Wang <shengjiu.wang@nxp.com>
pull/10/head
Robin Gong 2018-09-07 21:57:18 +08:00 committed by Jason Liu
parent 9424bb5b8d
commit 4a3ebbdc7c
1 changed files with 1 additions and 18 deletions
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19
drivers/dma/imx-sdma.c
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@ -1116,23 +1116,6 @@ static int sdma_disable_channel(struct dma_chan *chan)
return 0;
}
static int sdma_terminate_all(struct dma_chan *chan);
static int sdma_terminate_all_with_delay(struct dma_chan *chan)
{
sdma_terminate_all(chan);
/*
* According to NXP R&D team a delay of one BD SDMA cost time
* (maximum is 1ms) should be added after disable of the channel
* bit, to ensure SDMA core has really been stopped after SDMA
* clients call .device_terminate_all.
*/
mdelay(1);
return 0;
}
static void sdma_set_watermarklevel_for_p2p(struct sdma_channel *sdmac)
{
struct sdma_engine *sdma = sdmac->sdma;
@ -2398,7 +2381,7 @@ static int sdma_probe(struct platform_device *pdev)
sdma->dma_device.device_prep_slave_sg = sdma_prep_slave_sg;
sdma->dma_device.device_prep_dma_cyclic = sdma_prep_dma_cyclic;
sdma->dma_device.device_config = sdma_config;
sdma->dma_device.device_terminate_all = sdma_terminate_all_with_delay;
sdma->dma_device.device_terminate_all = sdma_terminate_all;
sdma->dma_device.device_pause = sdma_channel_pause;
sdma->dma_device.device_resume = sdma_channel_resume;
sdma->dma_device.src_addr_widths = SDMA_DMA_BUSWIDTHS;