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

Commit 73631813 authored by Jiada Wang's avatar Jiada Wang Committed by Greg Kroah-Hartman
Browse files

serial: imx: use locking to stop concurrent access of UCR1 



Several places are accessing the UCR1 register without locking.
This probably will cause a race issue when another thread
is accessing the same register.
Add locking to preventing concurrent access of the UCR1 register.

Signed-off-by: default avatarJiada Wang <jiada_wang@mentor.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 55d8693a

drivers/tty/serial/imx.c

+12 −0
Original line number Diff line number Diff line
@@ -731,6 +731,9 @@ static int start_rx_dma(struct imx_port *sport); 
static void imx_dma_rxint(struct imx_port *sport)

{

	unsigned long temp;

	unsigned long flags;



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



	temp = readl(sport->port.membase + USR2);

	if ((temp & USR2_RDR) && !sport->dma_is_rxing) {
@@ -744,6 +747,8 @@ static void imx_dma_rxint(struct imx_port *sport) 
		/* tell the DMA to receive the data. */

		start_rx_dma(sport);

	}



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

}



static irqreturn_t imx_int(int irq, void *dev_id)
@@ -873,6 +878,9 @@ static int imx_setup_ufcr(struct imx_port *sport, unsigned int mode) 
static void imx_rx_dma_done(struct imx_port *sport)

{

	unsigned long temp;

	unsigned long flags;



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



	/* Enable this interrupt when the RXFIFO is empty. */

	temp = readl(sport->port.membase + UCR1);
@@ -884,6 +892,8 @@ static void imx_rx_dma_done(struct imx_port *sport) 
	/* Is the shutdown waiting for us? */

	if (waitqueue_active(&sport->dma_wait))

		wake_up(&sport->dma_wait);



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

}



/*
@@ -1194,9 +1204,11 @@ static void imx_shutdown(struct uart_port *port) 
			dmaengine_terminate_all(sport->dma_chan_tx);

			dmaengine_terminate_all(sport->dma_chan_rx);

		}

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

		imx_stop_tx(port);

		imx_stop_rx(port);

		imx_disable_dma(sport);

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

		imx_uart_dma_exit(sport);

	}