serial: 8250, increase PASS_LIMIT

commit e7328ae1848966181a7ac47e8ae6cddbd2cf55f3 upstream.

With virtual machines like qemu, it's pretty common to see "too much
work for irq4" messages nowadays. This happens when a bunch of output
is printed on the emulated serial console. This is caused by too low
PASS_LIMIT. When ISR loops more than the limit, it spits the message.

I've been using a kernel with doubled the limit and I couldn't see no
problems. Maybe it's time to get rid of the message now?

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
[PG: drivers/tty/serial/8250.c ---> drivers/serial/8250.c in 2.6.34]
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index c1d79a2334761410fa76bef35ff1a4fef8d49c6e..848894773c642eeec64f80ce2fa68d3a0ba4c05e 100644 (file)
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -82,7 +82,7 @@ static unsigned int skip_txen_test; /* force skip of txen test at init time */
 #define DEBUG_INTR(fmt...)     do { } while (0)
 #endif
 
-#define PASS_LIMIT     256
+#define PASS_LIMIT     512
 
 #define BOTH_EMPTY     (UART_LSR_TEMT | UART_LSR_THRE)