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 <smbarber@chromium.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c
index 4fc3ffb..31e9c49 100644
--- a/drivers/dma/pl330.c
+++ b/drivers/dma/pl330.c
@@ -2274,7 +2274,7 @@
{
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 @@
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 @@
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;