serial/8250: Increase number of serial ports to 32

This will make sure that multiple serial port cards can be used out of the box. Otherwise the user must pass nr_uarts parameter, that will be often forgotten and increases support requests for serial card vendors.

Quoted 4 lines

This will make sure that multiple serial port cards can be used out of the box. Otherwise the user must pass nr_uarts parameter, that will be often forgotten and increases support requests for serial card vendors.

Has this really happened in the past?

What is the downside of changing
this option that has been around for many years now? Also note that multi-port serial cards are more rare these days than they used to be so changing this seems a bit pointless now.

Am 10.11.2010 17:08, schrieb Greg KH:

Quoted 6 lines · Yegor Yefremov

Quoted 4 lines

This will make sure that multiple serial port cards can be used out of the box. Otherwise the user must pass nr_uarts parameter, that will be often forgotten and increases support requests for serial card vendors.

Has this really happened in the past?

It is still the case. The most requests that we get are "the card doesn't function under Ubuntu...". After examining dmesg one could see that 8250 driver is initialized with 4 UARTS.

There are also lots of questions and bugs concerning this subject. Like this one:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/125524. I even found some entries from 2010:
http://www.gnulinux.in/forum/4-port-serial-card-installation-fedora-11

Quoted 4 lines

What is the downside of changing
this option that has been around for many years now? Also note that multi-port serial cards are more rare these days than they used to be so changing this seems a bit pointless now.

I can say that those cards are still selling. They're not dead.

The downside is that those card are not working out of the box and users not experienced in Linux often miss this parameter. Also some Live Linuxes like Ubuntu (perhaps I missed something) don't provide command line parameter, so you have to reload the driver with proper parameter.

I understand that it is somehow a responsibility of distribution maintainers to properly configure the kernel, but I hope that if vanilla kernel would increase default value, then they will also follow.

Quoted 4 lines · Yegor Yefremov

This will make sure that multiple serial port cards can be used out of the box. Otherwise the user must pass nr_uarts parameter, that will be often forgotten and increases support requests for serial card vendors.

Has this really happened in the past?  What is the downside of changing this option that has been around for many years now?  Also note that multi-port serial cards are more rare these days than they used to be so changing this seems a bit pointless now.

Quoted 11 lines · Greg KH

Quoted 4 lines · Yegor Yefremov

This will make sure that multiple serial port cards can be used out of the box. Otherwise the user must pass nr_uarts parameter, that will be often forgotten and increases support requests for serial card vendors.

Has this really happened in the past? ?What is the downside of changing this option that has been around for many years now? ?Also note that multi-port serial cards are more rare these days than they used to be so changing this seems a bit pointless now.

Multiport serial cards are not dead, we still sell bunches. This is one of those problems that really frustrates our customers. They want their ports to show up by default and the only way to do it is to recompile the kernel or modify the boot line. A lot of my customers don't like the 82510.nr_uarts work around in grub and so we have to hold their hands while they figure out how to recompile the kernel with support for more ports. I think the default number of ports should definitely be changed from 4 to at least 8, maybe even 16 or 32.

Quoted 13 lines · Matt Schulte

Quoted 11 lines · Greg KH

Quoted 4 lines · Yegor Yefremov

This will make sure that multiple serial port cards can be used out of the box. Otherwise the user must pass nr_uarts parameter, that will be often forgotten and increases support requests for serial card vendors.

Has this really happened in the past? ?What is the downside of changing this option that has been around for many years now? ?Also note that multi-port serial cards are more rare these days than they used to be so changing this seems a bit pointless now.

Quoted 9 lines

Multiport serial cards are not dead, we still sell bunches.  This is one of those problems that really frustrates our customers.  They want their ports to show up by default and the only way to do it is to recompile the kernel or modify the boot line.  A lot of my customers don't like the 82510.nr_uarts work around in grub and so we have to hold their hands while they figure out how to recompile the kernel with support for more ports.  I think the default number of ports should definitely be changed from 4 to at least 8, maybe even 16 or 32.

Why not work with the distros to get it changed?  If we change the default within the kernel, it's still not going to change what they are using at all, so you will still be having the same problem you are today.

Quoted 24 lines · Greg KH

Quoted 22 lines · Matt Schulte

Quoted 11 lines · Greg KH

Quoted 4 lines · Yegor Yefremov

This will make sure that multiple serial port cards can be used out of the box. Otherwise the user must pass nr_uarts parameter, that will be often forgotten and increases support requests for serial card vendors.

Has this really happened in the past? ?What is the downside of changing this option that has been around for many years now? ?Also note that multi-port serial cards are more rare these days than they used to be so changing this seems a bit pointless now.

Multiport serial cards are not dead, we still sell bunches. ?This is one of those problems that really frustrates our customers. ?They want their ports to show up by default and the only way to do it is to recompile the kernel or modify the boot line. ?A lot of my customers don't like the 82510.nr_uarts work around in grub and so we have to hold their hands while they figure out how to recompile the kernel with support for more ports. ?I think the default number of ports should definitely be changed from 4 to at least 8, maybe even 16 or 32.

Quoted 4 lines

Why not work with the distros to get it changed? ?If we change the default within the kernel, it's still not going to change what they are using at all, so you will still be having the same problem you are today.

Don't you think changing it here would eventually propagate down the chain to all of the distros? Or do you think they would ignore the change up here?

Quoted 10 lines

Quoted 6 lines

Quoted 5 lines

This will make sure that multiple serial port cards can be used out of the box. Otherwise the user must pass nr_uarts parameter, that will be often forgotten and increases support requests for serial card vendors.

Has this really happened in the past?

It is still the case. The most requests that we get are "the card doesn't function under Ubuntu...". After examining dmesg one could see that 8250 driver is initialized with 4 UARTS.

Quoted 5 lines

There are also lots of questions and bugs concerning this subject. Like this one:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/125524. I even found some entries from 2010:
http://www.gnulinux.in/forum/4-port-serial-card-installation-fedora-11

Then get the distro to change the default setting of their kernels.

Quoted 12 lines

Quoted 4 lines

What is the downside of changing
this option that has been around for many years now? Also note that multi-port serial cards are more rare these days than they used to be so changing this seems a bit pointless now.

I can say that those cards are still selling. They're not dead.

The downside is that those card are not working out of the box and users not experienced in Linux often miss this parameter. Also some Live Linuxes like Ubuntu (perhaps I missed something) don't provide command line parameter, so you have to reload the driver with proper parameter.

Quoted 4 lines

I understand that it is somehow a responsibility of distribution maintainers to properly configure the kernel, but I hope that if vanilla kernel would increase default value, then they will also follow.

I doubt it as they would never notice that the value changed at all (they run 'make oldconfig'). So please just work with the distros that you are having problems with to get the value changed.