The system could deadlock handling RX IRQs when RX-related IRQ
conditions became true while the receiver was disabled. To avoid this,
enable/disable the RX/TX IRQs together with the receiver/transmitter.
Signed-off-by: Soren Brinkmann <soren.brinkmann@xxxxxxxxxx>
---
drivers/tty/serial/xilinx_uartps.c | 17 +++++++++++------
1 file changed, 11 insertions(+), 6 deletions(-)
diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c
index 5da1c51e9e40..a0039cbcf812 100644
--- a/drivers/tty/serial/xilinx_uartps.c
+++ b/drivers/tty/serial/xilinx_uartps.c
@@ -126,6 +126,10 @@ MODULE_PARM_DESC(rx_timeout, "Rx timeout, 1-255");
#define CDNS_UART_IXR_RXEMPTY 0x00000002 /* RX FIFO empty interrupt. */
#define CDNS_UART_IXR_MASK 0x00001FFF /* Valid bit mask */
+#define CDNS_UART_RX_IRQS (CDNS_UART_IXR_PARITY | CDNS_UART_IXR_FRAMING | \
+ CDNS_UART_IXR_OVERRUN | CDNS_UART_IXR_RXTRIG | \
+ CDNS_UART_IXR_TOUT)
+
/* Goes in read_status_mask for break detection as the HW doesn't do it*/
#define CDNS_UART_IXR_BRK 0x80000000
@@ -272,7 +276,8 @@ 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 (isrstatus & CDNS_UART_RX_IRQS)
+ cdns_uart_handle_rx(port, isrstatus);
/* Dispatch an appropriate handler */
if ((isrstatus & CDNS_UART_IXR_TXEMPTY) == CDNS_UART_IXR_TXEMPTY) {
@@ -580,9 +585,12 @@ static void cdns_uart_stop_rx(struct uart_port *port)
{
unsigned int regval;
+ /* Disable RX IRQs */
+ writel(CDNS_UART_RX_IRQS, port->membase + CDNS_UART_IDR_OFFSET);
+
+ /* Disable the receiver */
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);
}
@@ -820,10 +828,7 @@ static int cdns_uart_startup(struct uart_port *port)
}
/* Set the Interrupt Registers with desired interrupts */
- writel(CDNS_UART_IXR_TXEMPTY | CDNS_UART_IXR_PARITY |
- CDNS_UART_IXR_FRAMING | CDNS_UART_IXR_OVERRUN |
- CDNS_UART_IXR_RXTRIG | CDNS_UART_IXR_TOUT,
- port->membase + CDNS_UART_IER_OFFSET);
+ writel(CDNS_UART_RX_IRQS, port->membase + CDNS_UART_IER_OFFSET);
return 0;
}
--
2.7.0.3.g497ea1e
--
To unsubscribe from this list: send the line "unsubscribe linux-serial" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
