From d64e9a2c750930272492952c16f3f2c95311a6c9 Mon Sep 17 00:00:00 2001 From: Stephen Barber Date: Thu, 18 Aug 2016 17:59:59 -0700 Subject: dmaengine: pl330: fix residual for non-running BUSY descriptors Only one descriptor in the work list should be running at any given time, but it's possible to have an enqueued BUSY descriptor that has not yet transferred any data, or for a BUSY descriptor to linger briefly before transitioning to DONE. These cases should be handled to keep residual calculations consistent even with the non-running BUSY descriptors in the work list. Signed-off-by: Stephen Barber Signed-off-by: Vinod Koul --- drivers/dma/pl330.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c index 4fc3ffbd5ca0..31e9c49e5604 100644 --- a/drivers/dma/pl330.c +++ b/drivers/dma/pl330.c @@ -2274,7 +2274,7 @@ pl330_tx_status(struct dma_chan *chan, dma_cookie_t cookie, { enum dma_status ret; unsigned long flags; - struct dma_pl330_desc *desc, *running = NULL; + struct dma_pl330_desc *desc, *running = NULL, *last_enq = NULL; struct dma_pl330_chan *pch = to_pchan(chan); unsigned int transferred, residual = 0; @@ -2291,6 +2291,8 @@ pl330_tx_status(struct dma_chan *chan, dma_cookie_t cookie, if (pch->thread->req_running != -1) running = pch->thread->req[pch->thread->req_running].desc; + last_enq = pch->thread->req[pch->thread->lstenq].desc; + /* Check in pending list */ list_for_each_entry(desc, &pch->work_list, node) { if (desc->status == DONE) @@ -2298,6 +2300,15 @@ pl330_tx_status(struct dma_chan *chan, dma_cookie_t cookie, else if (running && desc == running) transferred = pl330_get_current_xferred_count(pch, desc); + else if (desc->status == BUSY) + /* + * Busy but not running means either just enqueued, + * or finished and not yet marked done + */ + if (desc == last_enq) + transferred = 0; + else + transferred = desc->bytes_requested; else transferred = 0; residual += desc->bytes_requested - transferred; -- cgit v1.2.3