Re: [BUG][2.6.8.1] serial driver hangs SMP kernel, but not the UP kernel

Russell King
2004-10-29T21:20:05Z

On Fri, Oct 29, 2004 at 04:04:40PM -0500, Tim_T_Murphy@Dell.com wrote:
> > Shouldn't 8250_pci setup the ports already for you? If not, what
> > needs to be done to achieve this. Using setserial to setup ports
> > for PCI cards isn't the preferred way of doing this.
>
> good question, i will have to understand more to answer it though.
> our product has used this method for almost 2 years now.

Well, if you forward lspci -vvx and the "maddr" and "irqno" information
(in private mail if you prefer) then I'll fix 8250_pci to work.

> > At a guess, you've enabled "low latency" setting on this port ?
>
> yes. here's a snippet from the script:
>
> echo -n "Starting ${racsvc}: "
> # set serial characteristics for RAC device
> setserial /dev/${ttyid} \
> port 0x${maddr} irq ${irqno} ^skip_test autoconfig
> setserial /dev/${ttyid} \
> uart 16550A low_latency baud_base 1382400 \
> close_delay 0 closing_wait infinite
> # now start pppd
> /sbin/modprobe -q ppp >/dev/null 2>&1
> /sbin/modprobe -q ppp_async >/dev/null 2>&1
> daemon pppd call ${service}
> RETVAL=$?

I think dropping low_latency will work around the problem for the time
being.

--
Russell King
Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/
maintainer of: 2.6 PCMCIA - http://pcmcia.arm.linux.org.uk/
2.6 Serial core