dmaengine: dw-axi-dmac: Only start idle channels

Attempting to start a non-idle channel causes an error message to be logged, and is inefficient. Test for emptiness of the desc_issued list before doing so. Signed-off-by: Phil Elwell <[email protected]>
raspberrypi · Nov 13, 2024 · 767a31f · 767a31f
1 parent 66aef6c
commit 767a31f
Showing 1 changed file with 3 additions and 1 deletion.
diff --git a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
@@ -536,9 +536,11 @@ static void dma_chan_issue_pending(struct dma_chan *dchan)
 {
 	struct axi_dma_chan *chan = dchan_to_axi_dma_chan(dchan);
 	unsigned long flags;
+	bool was_empty;
 
 	spin_lock_irqsave(&chan->vc.lock, flags);
-	if (vchan_issue_pending(&chan->vc))
+	was_empty = list_empty(&chan->vc.desc_issued);
+	if (vchan_issue_pending(&chan->vc) && was_empty)
 		axi_chan_start_first_queued(chan);
 	spin_unlock_irqrestore(&chan->vc.lock, flags);
 }