Commit b3696289 authored by Shubhrajyoti Datta's avatar Shubhrajyoti Datta Committed by Greg Kroah-Hartman
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tty: xilinx_uartps: Prevent writes when the controller is disabled 



Prevent writing to the fifo if the controller is disabled.

Signed-off-by: default avatarShubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Link: https://lore.kernel.org/r/20220729114748.18332-6-shubhrajyoti.datta@xilinx.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent b8a6c3b3

drivers/tty/serial/xilinx_uartps.c

+15 −0
Original line number Diff line number Diff line
@@ -1132,6 +1132,21 @@ static struct uart_driver cdns_uart_uart_driver; 
 */

static void cdns_uart_console_putchar(struct uart_port *port, unsigned char ch)

{

	unsigned int ctrl_reg;

	unsigned long timeout;



	timeout = jiffies + msecs_to_jiffies(1000);

	while (1) {

		ctrl_reg = readl(port->membase + CDNS_UART_CR);

		if (!(ctrl_reg & CDNS_UART_CR_TX_DIS))

			break;

		if (time_after(jiffies, timeout)) {

			dev_warn(port->dev,

				 "timeout waiting for Enable\n");

			return;

		}

		cpu_relax();

	}

	while (readl(port->membase + CDNS_UART_SR) & CDNS_UART_SR_TXFULL)

		cpu_relax();

	writel(ch, port->membase + CDNS_UART_FIFO);