From d2cfe9628c6187cafd1aac32a44dcd9ed7adb5fe Mon Sep 17 00:00:00 2001
From: Peter Korsgaard <jacmet@sunsite.dk>
Date: Wed, 9 Sep 2009 16:54:04 +0200
Subject: [PATCH] uartlite: support shared interrupt lines
Adapt isr to work with shared interrupt lines.
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
drivers/serial/uartlite.c | 15 ++++++++++-----
1 file changed, 10 insertions(+), 5 deletions(-)
diff --git a/drivers/serial/uartlite.c b/drivers/serial/uartlite.c
index 5d3a573d6994..377f2712289e 100644
--- a/drivers/serial/uartlite.c
+++ b/drivers/serial/uartlite.c
@@ -154,17 +154,22 @@ static int ulite_transmit(struct uart_port *port, int stat)
static irqreturn_t ulite_isr(int irq, void *dev_id)
{
struct uart_port *port = dev_id;
- int busy;
+ int busy, n = 0;
do {
int stat = readb(port->membase + ULITE_STATUS);
busy = ulite_receive(port, stat);
busy |= ulite_transmit(port, stat);
+ n++;
} while (busy);
- tty_flip_buffer_push(port->state->port.tty);
-
- return IRQ_HANDLED;
+ /* work done? */
+ if (n > 1) {
+ tty_flip_buffer_push(port->state->port.tty);
+ return IRQ_HANDLED;
+ } else {
+ return IRQ_NONE;
+ }
}
static unsigned int ulite_tx_empty(struct uart_port *port)
@@ -221,7 +226,7 @@ static int ulite_startup(struct uart_port *port)
int ret;
ret = request_irq(port->irq, ulite_isr,
- IRQF_DISABLED | IRQF_SAMPLE_RANDOM, "uartlite", port);
+ IRQF_SHARED | IRQF_SAMPLE_RANDOM, "uartlite", port);
if (ret)
return ret;
--
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