Re: serial/8250: Increase number of serial ports detected to 32

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

On Mon, Nov 15, 2010 at 10:31:22AM +0100, Uwe Kleine-König wrote:
> Hi Bastian,
> 
> On Thu, Nov 11, 2010 at 12:50:00PM +0100, Bastian Blank wrote:
> > On Thu, Nov 11, 2010 at 12:22:46PM +0100, Yegor Yefremov wrote:
> > > our company is developing multi port serial cards among other
> > > products. The main problem is, when the customers first install this
> > > devices especially those with 8 ports, they get only few ports
> > > detected, cause CONFIG_SERIAL_8250_RUNTIME_UARTS is set to 4 (at least
> > > by Lenny).
> > 
> > SERIAL_8250_NR_UARTS needs to be changed first.
> > 
> > >                                                     Serial interface is
> > > still not dead in spite of new technologies. So this change is really
> > > needed.
> > 
> > Well, someone could change the 8250 driver to actually allow
> > adding/removing ports on runtime, like everything else does it,
> > including the whole bunch of usb-serial drivers. The the time beeing,
> > there is a parameter nr_uarts.
> This popped up recently on linux-arm-kernel ML:
> 
> 	http://thread.gmane.org/gmane.linux.ports.arm.kernel/92400/focus=93334

The 8250 serial driver can handle up to 64 ports, and used to do so out
of the box.

However, people complained that they only had up to four ports, and
couldn't see the reason for having the ability to have soo many serial
ports, so things got reduced.  This is inspite of having the runtime
'nr_uarts' option...

-- 
Russell King