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Commit 47aceb92 authored by Geert Uytterhoeven's avatar Geert Uytterhoeven Committed by Greg Kroah-Hartman
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serial: sh-sci: Do not resubmit DMA descriptors 



Resubmission of DMA descriptors is explicitly forbidden by the DMA
engine API.

Hence pass DMA_CTRL_ACK to dmaengine_prep_slave_sg(), and prepare a new
DMA descriptor instead of reusing the old one.
Remove sci_port.desc_rx[], as there's no longer a need to access the
active descriptor.

Signed-off-by: default avatarGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 658daa95

drivers/tty/serial/sh-sci.c

+18 −12
Original line number Original line Diff line number Diff line
@@ -104,7 +104,6 @@ struct sci_port { 
	struct dma_chan			*chan_rx;

	struct dma_chan			*chan_rx;





#ifdef CONFIG_SERIAL_SH_SCI_DMA

#ifdef CONFIG_SERIAL_SH_SCI_DMA

	struct dma_async_tx_descriptor	*desc_rx[2];

	dma_cookie_t			cookie_tx;

	dma_cookie_t			cookie_tx;

	dma_cookie_t			cookie_rx[2];

	dma_cookie_t			cookie_rx[2];

	dma_cookie_t			active_rx;

	dma_cookie_t			active_rx;
@@ -1397,11 +1396,11 @@ static void sci_submit_rx(struct sci_port *s) 
		struct dma_async_tx_descriptor *desc;

		struct dma_async_tx_descriptor *desc;





		desc = dmaengine_prep_slave_sg(chan,

		desc = dmaengine_prep_slave_sg(chan,

			sg, 1, DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT);

			sg, 1, DMA_DEV_TO_MEM,

			DMA_PREP_INTERRUPT | DMA_CTRL_ACK);

		if (!desc)

		if (!desc)

			goto fail;

			goto fail;





		s->desc_rx[i] = desc;

		desc->callback = sci_dma_rx_complete;

		desc->callback = sci_dma_rx_complete;

		desc->callback_param = s;

		desc->callback_param = s;

		s->cookie_rx[i] = dmaengine_submit(desc);

		s->cookie_rx[i] = dmaengine_submit(desc);
@@ -1420,10 +1419,8 @@ static void sci_submit_rx(struct sci_port *s) 
fail:

fail:

	if (i)

	if (i)

		dmaengine_terminate_all(chan);

		dmaengine_terminate_all(chan);

	for (i = 0; i < 2; i++) {

	for (i = 0; i < 2; i++)

		s->desc_rx[i] = NULL;

		s->cookie_rx[i] = -EINVAL;

		s->cookie_rx[i] = -EINVAL;

	}

	s->active_rx = -EINVAL;

	s->active_rx = -EINVAL;

	dev_warn(s->port.dev, "Failed to re-start Rx DMA, using PIO\n");

	dev_warn(s->port.dev, "Failed to re-start Rx DMA, using PIO\n");

	sci_rx_dma_release(s, true);

	sci_rx_dma_release(s, true);
@@ -1447,7 +1444,6 @@ static void work_fn_rx(struct work_struct *work) 
			s->active_rx);

			s->active_rx);

		return;

		return;

	}

	}

	desc = s->desc_rx[new];





	status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);

	status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state);

	if (status != DMA_COMPLETE) {

	if (status != DMA_COMPLETE) {
@@ -1474,17 +1470,27 @@ static void work_fn_rx(struct work_struct *work) 
		return;

		return;

	}

	}





	desc = dmaengine_prep_slave_sg(s->chan_rx, &s->sg_rx[new], 1,

				       DMA_DEV_TO_MEM,

				       DMA_PREP_INTERRUPT | DMA_CTRL_ACK);

	if (!desc)

		goto fail;



	desc->callback = sci_dma_rx_complete;

	desc->callback_param = s;

	s->cookie_rx[new] = dmaengine_submit(desc);

	s->cookie_rx[new] = dmaengine_submit(desc);

	if (dma_submit_error(s->cookie_rx[new])) {

	if (dma_submit_error(s->cookie_rx[new]))

		dev_warn(port->dev, "Failed submitting Rx DMA descriptor\n");

		goto fail;

		sci_rx_dma_release(s, true);

		return;

	}





	s->active_rx = s->cookie_rx[!new];

	s->active_rx = s->cookie_rx[!new];





	dev_dbg(port->dev, "%s: cookie %d #%d, new active cookie %d\n",

	dev_dbg(port->dev, "%s: cookie %d #%d, new active cookie %d\n",

		__func__, s->cookie_rx[new], new, s->active_rx);

		__func__, s->cookie_rx[new], new, s->active_rx);

	return;



fail:

	dev_warn(port->dev, "Failed submitting Rx DMA descriptor\n");

	sci_rx_dma_release(s, true);

}

}





static void work_fn_tx(struct work_struct *work)

static void work_fn_tx(struct work_struct *work)