Re: Serial port initialization broken on Armada 370/XP due to"serial: 8250_dw: Don't use UPF_FIXED_TYPE"

From: Greg Kroah-Hartman
Date: Fri Mar 15 2013 - 16:25:15 EST


On Thu, Feb 28, 2013 at 02:34:21PM +0200, Heikki Krogerus wrote:
> Hi,
>
> On Thu, Feb 28, 2013 at 12:42:06PM +0100, Gregory CLEMENT wrote:
> > >> Would you agree with this kind of patch to fix the issue?
> > >>
> > >> diff --git a/drivers/tty/serial/8250/8250.c b/drivers/tty/serial/8250/8250.c
> > >> index e2ac25a..0b284c6 100644
> > >> --- a/drivers/tty/serial/8250/8250.c
> > >> +++ b/drivers/tty/serial/8250/8250.c
> > >> @@ -1119,7 +1119,7 @@ static void autoconfig(struct uart_8250_port *up, unsigned int probeflags)
> > >> serial_out(up, UART_LCR, 0);
> > >>
> > >> serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO);
> > >> - scratch = serial_in(up, UART_IIR) >> 6;
> > >> + scratch = (serial_in(up, UART_IIR) & 0xFF) >> 6;
> > >>
> > >> switch (scratch) {
> > >> case 0:
> > >
> > > Instead, can you test if it's enough for you to set the reg-io-width
> > > to 1 instead of 4:
> >
> > Yes indeed it worked and it seems to be the correct description of my
> > hardware. So I will fix the dtsi file.
> >
> > However isn't buggy to use a function as it returned a char whereas
> > it returns an int?
>
> Yes, the driver should probable be cleaned.
>
> It seems to be happening in quite a few places in 8250.c.
> autoconfig_16550a() has pretty much identical code in it, where
> UART_IIR is read to unsigned char and shifted without a mask.

Can someone send me the correct fix here, if they want it included in
3.9-final?

thanks,

greg k-h
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