>>>> 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 > Then get the distro to change the default setting of their kernels. > >>> 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. > 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. I just want to summarize the effort of increasing the number of run-time UARTs. openSUSE and Ubuntu both accepted this change without long discussion: https://bugzilla.novell.com/show_bug.cgi?id=652954 https://bugs.launchpad.net/ubuntu/+bug/675453 ReHat/Fedora rejected the change without really acceptable reason: https://bugzilla.redhat.com/show_bug.cgi?id=657530 By Debian is the question still in discussion: http://lists.debian.org/debian-kernel/2010/11/msg00211.html Uwe pointed to the discussion about making 8250 UART detection dynamically: http://lists.debian.org/debian-kernel/2010/11/msg00286.html. Yegor -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
