Re: [PATCH v2] serial: 8250_dw: Improve unwritable LCR workaround

James Hogan
2013-12-10T22:48:18Z

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On Tuesday 10 December 2013 09:11:55 Ezequiel Garcia wrote:
> Hi Tim, James:
>
> On Mon, Dec 09, 2013 at 04:42:23PM -0800, Tim Kryger wrote:
> > On Fri, Dec 6, 2013 at 4:59 PM, James Hogan <james.hogan@imgtec.com>
wrote:
> [..]
>
> > diff --git a/drivers/tty/serial/8250/8250_dw.c
> > b/drivers/tty/serial/8250/8250_dw.c
> > index 4658e3e..5f096c7 100644
> > --- a/drivers/tty/serial/8250/8250_dw.c
> > +++ b/drivers/tty/serial/8250/8250_dw.c
> > @@ -96,7 +96,8 @@ static void dw8250_serial_out(struct uart_port *p,
> > int offset, int value)
> >
> > if (offset == UART_LCR) {
> >
> > int tries = 1000;
> > while (tries--) {
> >
> > - if (value == p->serial_in(p, UART_LCR))
> > + unsigned int lcr = p->serial_in(p, UART_LCR);
> > + if ((value & ~UART_LCR_SPAR) == (lcr &
> > ~UART_LCR_SPAR))>
> > return;
> >
> > dw8250_force_idle(p);
> > writeb(value, p->membase + (UART_LCR <<
> > p->regshift));
> >
> > @@ -132,7 +133,8 @@ static void dw8250_serial_out32(struct uart_port
> > *p, int offset, int value)
> >
> > if (offset == UART_LCR) {
> >
> > int tries = 1000;
> > while (tries--) {
> >
> > - if (value == p->serial_in(p, UART_LCR))
> > + unsigned int lcr = p->serial_in(p, UART_LCR);
> > + if ((value & ~UART_LCR_SPAR) == (lcr &
> > ~UART_LCR_SPAR))>
> > return;
> >
> > dw8250_force_idle(p);
> > writel(value, p->membase + (UART_LCR <<
> > p->regshift));
> >
> > Would you mind posting this for proper review so we can get the fix in?
>
> Applying this change fixes all the problems I reported (just did a quick
> test on the board I have currently on my desk).
>
> Nice work!

Thanks for testing it.

I've posted Tim's version for proper review with both your tested-by.

Cheers
James

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