serial: omap-serial: Enable the UART wake-up bits always

OMAP can do also dynamic idling so wake-up enable register should be set also while system is running. If UART_OMAP_WER is not set, then for instance the RX activity cannot wake up the UART port that is sleeping.

This RX wake-up feature was working when the 8250 driver was used instead of omap-serial. Reason for this is that the 8250 doesn't set the UART_OMAP_WER and then arch/arm/mach-omap2/pm34xx.c ends up saving and restoring the reset default which is the same than value OMAP_UART_WER_MOD_WKUP here.

Fix this by moving the conditional UART_OMAP_WER write from serial_omap_pm into serial_omap_startup where wake-up bits are set unconditionally.

---
This problem has been here since 2.6.37 when the omap-serial was switched into use so this patch is for 2.6.39.

---
 drivers/serial/omap-serial.c |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)

index 7f2f010..d40924a 100644
@@ -517,6 +517,9 @@ static int serial_omap_startup(struct uart_port *port)
 	up->ier = UART_IER_RLSI | UART_IER_RDI;
 	serial_out(up, UART_IER, up->ier);
 
+	/* Enable module level wake up */
+	serial_out(up, UART_OMAP_WER, OMAP_UART_WER_MOD_WKUP);
+
 	up->port_activity = jiffies;
 	return 0;
 }

@@ -824,9 +827,6 @@ serial_omap_pm(struct uart_port *port, unsigned int state,
 	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
 	serial_out(up, UART_EFR, efr);
 	serial_out(up, UART_LCR, 0);
-	/* Enable module level wake up */
-	serial_out(up, UART_OMAP_WER,
-		(state != 0) ? OMAP_UART_WER_MOD_WKUP : 0);
 }
 
 static void serial_omap_release_port(struct uart_port *port)

1.7.0.4

For omap folks:

1. This patch is coming through tty tree
http://git.kernel.org/?p=linux/kernel/git/gregkh/tty-2.6.git;a=commit;h=78841462d72fe7038cb7ea48adecc6fc395f2dc5

2. This patch helps those boards that don't have UART RTS signal (e.g. BeagleBoard) and thus padconf wakeup mechanism is not available.

Jarkko