Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit a2c718ce authored by Dirk Behme's avatar Dirk Behme Committed by Greg Kroah-Hartman
Browse files

serial: imx: disable TDMAEN in imx_flush_buffer() 



Terminating the DMA, make sure the interrupt is disabled, too.
This fixes random kernel Oops due to dma_tx_call() called for
invalid transmissions.

If we disable the TDMAEN, make sure it's enabled again if a TX
DMA is started.

Signed-off-by: default avatarJiada Wang <jiada_wang@mentor.com>
Signed-off-by: default avatarDirk Behme <dirk.behme@de.bosch.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 0bbc9b81

drivers/tty/serial/imx.c

+15 −0
Original line number Diff line number Diff line
@@ -502,11 +502,16 @@ static void dma_tx_callback(void *data) 
	struct scatterlist *sgl = &sport->tx_sgl[0];

	struct circ_buf *xmit = &sport->port.state->xmit;

	unsigned long flags;

	unsigned long temp;



	spin_lock_irqsave(&sport->port.lock, flags);



	dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);



	temp = readl(sport->port.membase + UCR1);

	temp &= ~UCR1_TDMAEN;

	writel(temp, sport->port.membase + UCR1);



	/* update the stat */

	xmit->tail = (xmit->tail + sport->tx_bytes) & (UART_XMIT_SIZE - 1);

	sport->port.icount.tx += sport->tx_bytes;
@@ -539,6 +544,7 @@ static void imx_dma_tx(struct imx_port *sport) 
	struct dma_async_tx_descriptor *desc;

	struct dma_chan	*chan = sport->dma_chan_tx;

	struct device *dev = sport->port.dev;

	unsigned long temp;

	int ret;



	if (sport->dma_is_txing)
@@ -575,6 +581,11 @@ static void imx_dma_tx(struct imx_port *sport) 


	dev_dbg(dev, "TX: prepare to send %lu bytes by DMA.\n",

			uart_circ_chars_pending(xmit));



	temp = readl(sport->port.membase + UCR1);

	temp |= UCR1_TDMAEN;

	writel(temp, sport->port.membase + UCR1);



	/* fire it */

	sport->dma_is_txing = 1;

	dmaengine_submit(desc);
@@ -1258,6 +1269,7 @@ static void imx_flush_buffer(struct uart_port *port) 
{

	struct imx_port *sport = (struct imx_port *)port;

	struct scatterlist *sgl = &sport->tx_sgl[0];

	unsigned long temp;



	if (!sport->dma_chan_tx)

		return;
@@ -1267,6 +1279,9 @@ static void imx_flush_buffer(struct uart_port *port) 
	if (sport->dma_is_txing) {

		dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents,

			     DMA_TO_DEVICE);

		temp = readl(sport->port.membase + UCR1);

		temp &= ~UCR1_TDMAEN;

		writel(temp, sport->port.membase + UCR1);

		sport->dma_is_txing = false;

	}

}