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[PATH RESEND v2 09/10] tty: xuartps: Only handle RX IRQs when RX is enabled

From Soren Brinkmann <soren.brinkmann@xilinx.com>
Newsgroups linux.kernel
Subject [PATH RESEND v2 09/10] tty: xuartps: Only handle RX IRQs when RX is enabled
Date 2015-11-19 21:20 +0100
Message-ID <qwDQu-5IW-23@gated-at.bofh.it> (permalink)
References <qwDGO-5Ex-27@gated-at.bofh.it>
Organization linux.* mail to news gateway

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Ignore RX-related interrupts if RX is not enabled.

Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
---
 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 aa1176e6661a..413229661f5d 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) {
@@ -576,11 +583,13 @@ 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;
 }
 
 /**
@@ -761,6 +770,7 @@ 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);
@@ -787,6 +797,7 @@ 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.
@@ -830,6 +841,7 @@ 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);
 
@@ -841,6 +853,7 @@ 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);
 
-- 
2.6.3.3.g9bb996a

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Thread

[PATH RESEND v2 00/10] tty: xuartps: Fix lock ups Soren Brinkmann <soren.brinkmann@xilinx.com> - 2015-11-19 21:20 +0100
  [PATH RESEND v2 03/10] tty: xuartps: Always enable transmitter in start_tx Soren Brinkmann <soren.brinkmann@xilinx.com> - 2015-11-19 21:20 +0100
    Re: [PATH RESEND v2 03/10] tty: xuartps: Always enable transmitter in  start_tx Peter Hurley <peter@hurleysoftware.com> - 2015-11-20 13:20 +0100
      Re: [PATH RESEND v2 03/10] tty: xuartps: Always enable transmitter  in start_tx Sören Brinkmann <soren.brinkmann@xilinx.com> - 2015-11-20 16:30 +0100
        Re: [PATH RESEND v2 03/10] tty: xuartps: Always enable transmitter in  start_tx Peter Hurley <peter@hurleysoftware.com> - 2015-11-20 17:40 +0100
          Re: [PATH RESEND v2 03/10] tty: xuartps: Always enable transmitter  in start_tx Sören Brinkmann <soren.brinkmann@xilinx.com> - 2015-11-20 18:00 +0100
            Re: [PATH RESEND v2 03/10] tty: xuartps: Always enable transmitter in  start_tx Peter Hurley <peter@hurleysoftware.com> - 2015-11-20 18:20 +0100
              Re: [PATH RESEND v2 03/10] tty: xuartps: Always enable transmitter  in start_tx Sören Brinkmann <soren.brinkmann@xilinx.com> - 2015-11-20 18:30 +0100
              Re: [PATH RESEND v2 03/10] tty: xuartps: Always enable transmitter in  start_tx Michal Simek <michal.simek@xilinx.com> - 2015-11-23 08:10 +0100
                Re: [PATH RESEND v2 03/10] tty: xuartps: Always enable transmitter in  start_tx Peter Hurley <peter@hurleysoftware.com> - 2015-11-23 21:10 +0100
                Re: [PATH RESEND v2 03/10] tty: xuartps: Always enable transmitter in  start_tx Michal Simek <michal.simek@xilinx.com> - 2015-11-24 08:50 +0100
      Re: [PATH RESEND v2 03/10] tty: xuartps: Always enable transmitter  in start_tx Sören Brinkmann <soren.brinkmann@xilinx.com> - 2015-11-20 18:10 +0100
        Re: [PATH RESEND v2 03/10] tty: xuartps: Always enable transmitter in  start_tx Peter Hurley <peter@hurleysoftware.com> - 2015-11-20 18:20 +0100
  [PATH RESEND v2 05/10] tty: xuartps: Improve startup function Soren Brinkmann <soren.brinkmann@xilinx.com> - 2015-11-19 21:20 +0100
  [PATH RESEND v2 08/10] tty: xuartps: Move RX path into helper function Soren Brinkmann <soren.brinkmann@xilinx.com> - 2015-11-19 21:20 +0100
  [PATH RESEND v2 06/10] tty: xuartps: Keep lock for whole ISR Soren Brinkmann <soren.brinkmann@xilinx.com> - 2015-11-19 21:20 +0100
  [PATH RESEND v2 09/10] tty: xuartps: Only handle RX IRQs when RX is enabled Soren Brinkmann <soren.brinkmann@xilinx.com> - 2015-11-19 21:20 +0100
  [PATH RESEND v2 10/10] tty: xuartps: Cleanup: Reformat if-else Soren Brinkmann <soren.brinkmann@xilinx.com> - 2015-11-19 21:20 +0100
  [PATH RESEND v2 07/10] tty: xuartps: Acquire port lock for shutdown Soren Brinkmann <soren.brinkmann@xilinx.com> - 2015-11-19 21:20 +0100
  [PATH RESEND v2 01/10] tty: xuartps: Beautify read-modify writes Soren Brinkmann <soren.brinkmann@xilinx.com> - 2015-11-19 21:20 +0100
  [PATH RESEND v2 02/10] tty: xuartps: Use spinlock to serialize HW access Soren Brinkmann <soren.brinkmann@xilinx.com> - 2015-11-19 21:20 +0100

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