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authorJohn Linn <john.linn@xilinx.com>2013-03-22 18:49:27 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-03-25 16:26:23 -0700
commit855f6fd941019ecc9525ca038b78f50c6c1e80a8 (patch)
treea9552229d60c0b3930aa57187e6c034574fb9b1f
parent9326b047e4fd4a8da72e59d913214a1803e9709c (diff)
Xilinx: ARM: UART: clear pending irqs before enabling irqs
The Boot ROM has an issue which will cause the driver to lock up as pending irqs are not being cleared. With them cleared it prevents that issue. This patch is needed for the current (3.9-rc3) mainline kernel. I guess it went unnoticed, because it was only tested with u-boot up until now. And u-boot maybe handles this. [s.trumtrar@pengutronix.de: cherry-picked from linux-xlnx.git] Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/tty/serial/xilinx_uartps.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c
index ba451c7209fc..f36bbba1ac8b 100644
--- a/drivers/tty/serial/xilinx_uartps.c
+++ b/drivers/tty/serial/xilinx_uartps.c
@@ -578,6 +578,8 @@ static int xuartps_startup(struct uart_port *port)
/* Receive Timeout register is enabled with value of 10 */
xuartps_writel(10, XUARTPS_RXTOUT_OFFSET);
+ /* Clear out any pending interrupts before enabling them */
+ xuartps_writel(xuartps_readl(XUARTPS_ISR_OFFSET), XUARTPS_ISR_OFFSET);
/* Set the Interrupt Registers with desired interrupts */
xuartps_writel(XUARTPS_IXR_TXEMPTY | XUARTPS_IXR_PARITY |