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

[Russell King <rmk+lkml@arm.linux.org.uk>]

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