diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c index fcecbaddb351a7c711764e18d5a149f86b2ab612..fa9d75adf4d73171142595a5c60508dcad742513 100644 --- a/drivers/dma/at_xdmac.c +++ b/drivers/dma/at_xdmac.c @@ -879,7 +879,7 @@ at_xdmac_tx_status(struct dma_chan *chan, dma_cookie_t cookie, struct list_head *descs_list; enum dma_status ret; int residue; - u32 cur_nda; + u32 cur_nda, mask, value; u8 dwidth = at_xdmac_get_dwidth(atchan->cfg[AT_XDMAC_CUR_CFG]); ret = dma_cookie_status(chan, cookie, txstate); @@ -903,10 +903,17 @@ at_xdmac_tx_status(struct dma_chan *chan, dma_cookie_t cookie, } residue = desc->xfer_size; - /* Flush FIFO. */ - at_xdmac_write(atxdmac, AT_XDMAC_GSWF, atchan->mask); - while (!(at_xdmac_chan_read(atchan, AT_XDMAC_CIS) & AT_XDMAC_CIS_FIS)) - cpu_relax(); + /* + * Flush FIFO: only relevant when the transfer is source peripheral + * synchronized. + */ + mask = AT_XDMAC_CC_TYPE | AT_XDMAC_CC_DSYNC; + value = AT_XDMAC_CC_TYPE_PER_TRAN | AT_XDMAC_CC_DSYNC_PER2MEM; + if ((atchan->cfg[AT_XDMAC_CUR_CFG] & mask) == value) { + at_xdmac_write(atxdmac, AT_XDMAC_GSWF, atchan->mask); + while (!(at_xdmac_chan_read(atchan, AT_XDMAC_CIS) & AT_XDMAC_CIS_FIS)) + cpu_relax(); + } cur_nda = at_xdmac_chan_read(atchan, AT_XDMAC_CNDA) & 0xfffffffc; /*