On 11/21/2015 09:59 PM, Soren Brinkmann wrote:
> Ignore RX-related interrupts if RX is not enabled.
This doesn't look like a safe approach; fast-forward a couple of years and
some is trying to add some feature but can't figure out why no data is
arriving...
What is this trying to solve?
Regards,
Peter Hurley
> Signed-off-by: Soren Brinkmann <soren.brinkmann@xxxxxxxxxx>
> ---
> drivers/tty/serial/xilinx_uartps.c | 15 ++++++++++++++-
> 1 file changed, 14 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c
> index db9e23eaf300..3a1e508926c1 100644
> --- a/drivers/tty/serial/xilinx_uartps.c
> +++ b/drivers/tty/serial/xilinx_uartps.c
> @@ -161,6 +161,7 @@ MODULE_PARM_DESC(rx_timeout, "Rx timeout, 1-255");
> * @pclk: APB clock
> * @baud: Current baud rate
> * @clk_rate_change_nb: Notifier block for clock changes
> + * @flags: Driver flags
> */
> struct cdns_uart {
> struct uart_port *port;
> @@ -168,7 +169,11 @@ struct cdns_uart {
> struct clk *pclk;
> unsigned int baud;
> struct notifier_block clk_rate_change_nb;
> + u32 flags;
> };
> +
> +#define CDNS_FLAG_RX_ENABLED BIT(0)
> +
> #define to_cdns_uart(_nb) container_of(_nb, struct cdns_uart, \
> clk_rate_change_nb);
>
> @@ -262,6 +267,7 @@ static void cdns_uart_handle_rx(struct uart_port *port, unsigned int isrstatus)
> static irqreturn_t cdns_uart_isr(int irq, void *dev_id)
> {
> struct uart_port *port = (struct uart_port *)dev_id;
> + struct cdns_uart *cdns_uart = port->private_data;
> unsigned long flags;
> unsigned int isrstatus, numbytes;
>
> @@ -272,7 +278,8 @@ static irqreturn_t cdns_uart_isr(int irq, void *dev_id)
> */
> isrstatus = readl(port->membase + CDNS_UART_ISR_OFFSET);
>
> - cdns_uart_handle_rx(port, isrstatus);
> + if (cdns_uart->flags & CDNS_FLAG_RX_ENABLED)
> + cdns_uart_handle_rx(port, isrstatus);
>
> /* Dispatch an appropriate handler */
> if ((isrstatus & CDNS_UART_IXR_TXEMPTY) == CDNS_UART_IXR_TXEMPTY) {
> @@ -579,11 +586,13 @@ static void cdns_uart_stop_tx(struct uart_port *port)
> static void cdns_uart_stop_rx(struct uart_port *port)
> {
> unsigned int regval;
> + struct cdns_uart *cdns_uart = port->private_data;
>
> regval = readl(port->membase + CDNS_UART_CR_OFFSET);
> regval |= CDNS_UART_CR_RX_DIS;
> /* Disable the receiver */
> writel(regval, port->membase + CDNS_UART_CR_OFFSET);
> + cdns_uart->flags &= ~CDNS_FLAG_RX_ENABLED;
> }
>
> /**
> @@ -764,6 +773,7 @@ static int cdns_uart_startup(struct uart_port *port)
> {
> unsigned long flags;
> unsigned int retval = 0, status = 0;
> + struct cdns_uart *cdns_uart = port->private_data;
>
> retval = request_irq(port->irq, cdns_uart_isr, 0, CDNS_UART_NAME,
> (void *)port);
> @@ -790,6 +800,7 @@ static int cdns_uart_startup(struct uart_port *port)
> status &= CDNS_UART_CR_RX_DIS;
> status |= CDNS_UART_CR_RX_EN;
> writel(status, port->membase + CDNS_UART_CR_OFFSET);
> + cdns_uart->flags |= CDNS_FLAG_RX_ENABLED;
>
> /* Set the Mode Register with normal mode,8 data bits,1 stop bit,
> * no parity.
> @@ -833,6 +844,7 @@ static void cdns_uart_shutdown(struct uart_port *port)
> {
> int status;
> unsigned long flags;
> + struct cdns_uart *cdns_uart = port->private_data;
>
> spin_lock_irqsave(&port->lock, flags);
>
> @@ -844,6 +856,7 @@ static void cdns_uart_shutdown(struct uart_port *port)
> /* Disable the TX and RX */
> writel(CDNS_UART_CR_TX_DIS | CDNS_UART_CR_RX_DIS,
> port->membase + CDNS_UART_CR_OFFSET);
> + cdns_uart->flags &= ~CDNS_FLAG_RX_ENABLED;
>
> spin_unlock_irqrestore(&port->lock, flags);
>
>
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