[PATCH v2 3/3] dma: mxs-dma: Report correct residue for cyclic DMA
From: Markus Pargmann <hidden>
Date: 2013-09-30 13:13:42
Subsystem:
dma generic offload engine subsystem, the rest · Maintainers:
Vinod Koul, Linus Torvalds
Use the channel's buffer address register to calculate correct residue value for tx_status. --- drivers/dma/mxs-dma.c | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-)
diff --git a/drivers/dma/mxs-dma.c b/drivers/dma/mxs-dma.c
index a696438..f99498b 100644
--- a/drivers/dma/mxs-dma.c
+++ b/drivers/dma/mxs-dma.c@@ -57,6 +57,8 @@ (((dma_is_apbh(d) && apbh_is_old(d)) ? 0x050 : 0x110) + (n) * 0x70) #define HW_APBHX_CHn_SEMA(d, n) \ (((dma_is_apbh(d) && apbh_is_old(d)) ? 0x080 : 0x140) + (n) * 0x70) +#define HW_APBHX_CHn_BAR(d, n) \ + (((dma_is_apbh(d) && apbh_is_old(d)) ? 0x070 : 0x130) + (n) * 0x70) /* * ccw bits definitions
@@ -627,8 +629,23 @@ static enum dma_status mxs_dma_tx_status(struct dma_chan *chan, dma_cookie_t cookie, struct dma_tx_state *txstate) { struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan); + struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma; + u32 residue = 0; + + if (mxs_chan->status == DMA_IN_PROGRESS && + mxs_chan->flags & MXS_DMA_SG_LOOP) { + struct mxs_dma_ccw *last_ccw; + u32 bar; + + last_ccw = &mxs_chan->ccw[mxs_chan->desc_count - 1]; + residue = last_ccw->xfer_bytes + last_ccw->bufaddr; + + bar = readl(mxs_dma->base + + HW_APBHX_CHn_BAR(mxs_dma, chan->chan_id)); + residue -= bar; + } - dma_set_tx_state(txstate, chan->completed_cookie, chan->cookie, 0); + dma_set_tx_state(txstate, chan->completed_cookie, chan->cookie, residue); return mxs_chan->status; }
--
1.8.4.rc3