[PATCH] iop: n2100: enable serial interrupt

[Mikael Pettersson]

Aaro Koskinen writes:
 > Thecus N2100 has a jumper (J3/J4) to select whether the XINT1 interrupt
 > line is connected to the second UHCI controller (position J3) or to
 > the serial port UART (position J4). Currently, the kernel is hardcoded
 > to assume the J3 position, and the serial port is always being used in
 > polling mode.
 > 
 > The patch adds the IRQ autodetection flag for the serial port interrupt,
 > and also marks it as shared (as the driver for the second UHCI controller
 > will request the interrupt in any case). Now, when the jumper is set to
 > the J4 position, the serial port will have an interrupt line, resulting
 > in less CPU overhead and faster throughput.
 > 
 > Signed-off-by: Aaro Koskinen <aaro.koskinen at iki.fi>
 > ---
 >  arch/arm/mach-iop32x/n2100.c |    2 +-
 >  1 files changed, 1 insertions(+), 1 deletions(-)
 > 
 > diff --git a/arch/arm/mach-iop32x/n2100.c b/arch/arm/mach-iop32x/n2100.c
 > index d2e4278..001db59 100644
 > --- a/arch/arm/mach-iop32x/n2100.c
 > +++ b/arch/arm/mach-iop32x/n2100.c
 > @@ -178,7 +178,7 @@ static struct plat_serial8250_port n2100_serial_port[] = {
 >  		.mapbase	= N2100_UART,
 >  		.membase	= (char *)N2100_UART,
 >  		.irq		= 0,
 > -		.flags		= UPF_SKIP_TEST,
 > +		.flags		= UPF_SKIP_TEST | UPF_AUTO_IRQ | UPF_SHARE_IRQ,
 >  		.iotype		= UPIO_MEM,
 >  		.regshift	= 0,
 >  		.uartclk	= 1843200,

Nice. When I tried using irq auto-detection for this back in September
I added UPF_AUTO_IRQ but missed the UPF_SHARE_IRQ thing, and that didn't
work. This one does work (with the jumper in position J4).

Tested-by: Mikael Pettersson <mikpe at it.uu.se>