Re: [PATCH] serial driver PMC MSP71xx, kernel linux-mips.git mast er

From: Marc St-Jean
Date: Mon Feb 12 2007 - 12:46:36 EST




Sergei Shtylyov wrote:
> Hello.
>
> Marc St-Jean wrote:
>
> >> > Fourth attempt at the serial driver patch for the PMC-Sierra MSP71xx
> >>device.
>
> I think you need to submit your patch to Andrew Morton since it
> requires a patch from his tree.

OK, will do.


> >> > @@ -1383,6 +1399,19 @@ static irqreturn_t serial8250_interrupt(
> >> > handled = 1;
> >> >
> >> > end = NULL;
> >> > + } else if (up->port.iotype == UPIO_DWAPB &&
> >> > + (iir & UART_IIR_BUSY) ==
> UART_IIR_BUSY) {
>
> >> Worth aligning this line with the opening paren of if... but's
> that's
> >>nitpicking. :-)
>
> > No problem I'll change it. I just usually align to the closest tab
> stop to
> > the opening parenthesis.
>
> It haven't really changed in the last patch. :-)

I will respin with 8 char tabs.


> >> > + /* The DesignWare APB UART has an Busy Detect
> >>(0x07)
> >> > + * interrupt meaning an LCR write attempt
> >>occured while the
> >> > + * UART was busy. The interrupt must be cleared
> >>by reading
> >> > + * the UART status register (USR) and the LCR
> >>re-written. */
> >> > + unsigned int status;
> >> > + status = *(volatile u32
> *)up->port.private_data;
> >> > + serial_out(up, UART_LCR, up->lcr);
> >> > +
> >> > + handled = 1;
> >> > +
> >> > + end = NULL;
> >> > } else if (end == NULL)
> >> > end = l;
> >> >
> >> > return 0;
>
> >> Still, shouldn't you be doing this in serial8250_timeout()
>
> > No, the serial8250_timeout is for issue 1 at the top, this is for
> > issue 2.
>
> It's for lost interrupts, IIUC. They use anothe timeout handler for the
> workaround...

This issue (2) is a completely new type of interrupt generated but the
DesignWare APB uart, it has nothing to do with lost interrupts.


> >>also?
> >>What IRQ numbers this UART is using, BTW?
>
> > For the ports on the device they are 27 and 42. Is there any
> significance
> > that I'm not aware of?
>
> Yeah, IRQ0 is treated as no IRQ by 8250, and in this case it falls
> back to
> using serial8250_timeout() to handle "interrupts".

Good to know. It won't be affecting us then.


>
> >> Oops, your mailer went and did it again. :-)
>
> > I'm completely giving up on Thunderbird,unless someone can point out
>
> Ypu should have long ago. :-)
>
> > the specific internal configuration items which needs a kick!
>
> Only the attachments will work in the Mozilla kind mailer, AFAIK.
> The last patch looked OK at last. :-)

The attachemnents appear to be MIME which is a no-no according the
linux FAQ at kernel.org. I guess I'll stick with /bin/mail.

Thanks,
Marc
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