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Commit c33b644c authored by Russell King's avatar Russell King
Browse files

dmaengine: PL08x: start next descriptor from irq context 



Rather than waiting for the tasklet to run, we can start the next
descriptor from interrupt context, as soon as we know that the
previous descriptor has completed.

Acked-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Tested-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent ea160561

drivers/dma/amba-pl08x.c

+5 −4
Original line number Diff line number Diff line
@@ -1671,10 +1671,7 @@ static void pl08x_tasklet(unsigned long data) 
	spin_lock_irqsave(&plchan->lock, flags);

	list_splice_tail_init(&plchan->done_list, &head);



	/* If a new descriptor is queued, set it up plchan->at is NULL here */

	if (!list_empty(&plchan->issued_list)) {

		pl08x_start_next_txd(plchan);

	} else if (!list_empty(&plchan->pend_list) || plchan->phychan_hold) {

	if (plchan->at || !list_empty(&plchan->pend_list) || plchan->phychan_hold) {

		/*

		 * This channel is still in use - we have a new txd being

		 * prepared and will soon be queued.  Don't give up the
@@ -1786,6 +1783,10 @@ static irqreturn_t pl08x_irq(int irq, void *dev) 
				pl08x_release_mux(plchan);

				dma_cookie_complete(&tx->tx);

				list_add_tail(&tx->node, &plchan->done_list);



				/* And start the next descriptor */

				if (!list_empty(&plchan->issued_list))

					pl08x_start_next_txd(plchan);

			}

			spin_unlock(&plchan->lock);