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Commit 71ab1c03 authored by Geert Uytterhoeven's avatar Geert Uytterhoeven Committed by Greg Kroah-Hartman
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serial: sh-sci: Resume PIO in sci_rx_interrupt() on DMA failure 



On (H)SCIF, sci_submit_rx() is called in the receive interrupt handler.
Hence if DMA submission fails, the interrupt handler should resume
handling reception using PIO, else no more data is received.

Make sci_submit_rx() return an error indicator, so the receive interrupt
handler can act appropriately.

Signed-off-by: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: default avatarSimon Horman <horms+renesas@verge.net.au>
Acked-by: default avatarWolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 2e948218

drivers/tty/serial/sh-sci.c

+8 −3
Original line number Diff line number Diff line
@@ -1331,7 +1331,7 @@ static void sci_tx_dma_release(struct sci_port *s) 
	dma_release_channel(chan);

}



static void sci_submit_rx(struct sci_port *s, bool port_lock_held)

static int sci_submit_rx(struct sci_port *s, bool port_lock_held)

{

	struct dma_chan *chan = s->chan_rx;

	struct uart_port *port = &s->port;
@@ -1359,7 +1359,7 @@ static void sci_submit_rx(struct sci_port *s, bool port_lock_held) 
	s->active_rx = s->cookie_rx[0];



	dma_async_issue_pending(chan);

	return;

	return 0;



fail:

	/* Switch to PIO */
@@ -1374,6 +1374,7 @@ static void sci_submit_rx(struct sci_port *s, bool port_lock_held) 
	sci_start_rx(port);

	if (!port_lock_held)

		spin_unlock_irqrestore(&port->lock, flags);

	return -EAGAIN;

}



static void work_fn_tx(struct work_struct *work)
@@ -1668,8 +1669,10 @@ static irqreturn_t sci_rx_interrupt(int irq, void *ptr) 
			disable_irq_nosync(irq);

			scr |= SCSCR_RDRQE;

		} else {

			if (sci_submit_rx(s, false) < 0)

				goto handle_pio;



			scr &= ~SCSCR_RIE;

			sci_submit_rx(s, false);

		}

		serial_port_out(port, SCSCR, scr);

		/* Clear current interrupt */
@@ -1681,6 +1684,8 @@ static irqreturn_t sci_rx_interrupt(int irq, void *ptr) 


		return IRQ_HANDLED;

	}



handle_pio:

#endif



	if (s->rx_trigger > 1 && s->rx_fifo_timeout > 0) {