diff options
| author | Robin Gong <b38343@freescale.com> | 2014-12-08 17:30:40 +0800 |
|---|---|---|
| committer | Nitin Garg <nitin.garg@nxp.com> | 2016-01-14 10:59:35 -0600 |
| commit | 31b3d3d83de18570774d1173d9654836c8236930 (patch) | |
| tree | 57dc6d647569af7c329cdf2cf4f4a63a0433f516 /drivers/dma | |
| parent | ae254208a0079dbacee9acc14eb4a6369cd2ee1c (diff) | |
MLK-9768: dma: imx-sdma: fix UART loopback random failed
For UART, we need use old chn_real_count to know the real rx count even in
cylic dma mode, because UART driver use cyclic mode to increase performance
without any data loss.
Signed-off-by: Robin Gong <b38343@freescale.com>
(cherry picked from commit 398cee2ad110c4f183e553af0564fbdcbe8548cb)
Diffstat (limited to 'drivers/dma')
| -rw-r--r-- | drivers/dma/imx-sdma.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c index d2c1f873fca9..0e35d82c22c5 100644 --- a/drivers/dma/imx-sdma.c +++ b/drivers/dma/imx-sdma.c @@ -1359,7 +1359,12 @@ static enum dma_status sdma_tx_status(struct dma_chan *chan, struct sdma_channel *sdmac = to_sdma_chan(chan); u32 residue; - if (sdmac->flags & IMX_DMA_SG_LOOP) + /* + * For uart rx data may not receive fully, use old chn_real_count to + * know the real rx count. + */ + if ((sdmac->flags & IMX_DMA_SG_LOOP) && + (sdmac->peripheral_type != IMX_DMATYPE_UART)) residue = (sdmac->num_bd - sdmac->buf_tail) * sdmac->period_len; else residue = sdmac->chn_count - sdmac->chn_real_count; |