diff options
| author | Jiada Wang <jiada_wang@mentor.com> | 2014-12-09 18:11:23 +0900 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-01-09 14:23:07 -0800 |
| commit | 73631813c1ed17437e9de86f82a477fa4bac90c1 (patch) | |
| tree | 1adfd7774d7b636ba899d3c013221cd131b9f1fc /drivers/tty/serial/imx.c | |
| parent | 55d8693acd65b1c14e011cbcbfad2a15626472cd (diff) | |
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: Jiada Wang <jiada_wang@mentor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/serial/imx.c')
| -rw-r--r-- | drivers/tty/serial/imx.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c index eb2210fa972e..c851247a27cb 100644 --- a/drivers/tty/serial/imx.c +++ b/drivers/tty/serial/imx.c @@ -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); } |