On 31/08/2018 16:38, Michal Kubecek wrote:
On Friday, 31 August 2018 8:20 Per Jessen wrote:
Andrei Borzenkov wrote:
30.08.2018 14:57, Per Jessen ?????:
32 does seem a pretty odd default.
Ubuntu has
CONFIG_SERIAL_8250_NR_UARTS=48 CONFIG_SERIAL_8250_RUNTIME_UARTS=32
So it is not something entirely specific to openSUSE.
Right - I guess it's a kernel default that was changed at some point. For amusement, going even further back in time - in 2.6.25 :
CONFIG_SERIAL_8250_NR_UARTS=4 CONFIG_SERIAL_8250_RUNTIME_UARTS=4
:-)
OK, let's go for some amusement. We have such tool, it's called "git" and it can tell you rather quickly where that "some point" was. And in this particular case, it could even point you to bsc#652954 and this bug then to
http://www.spinics.net/lists/linux-serial/msg03020.html
I don't say I agree with the reasoning, personally I think that four would be reasonable default for openSUSE (and you don't even have to put the module parameter on kernel command line, that's what /etc/modprobe.d exists for), but there is really no need to pretend there is some dark mystery about the change(s).
Michal Kubecek
Personally I think 4 is too low, especially for those who have worked in electrical engineering contexts, at my last job I commonly had 8-10 ports sometimes more, this was partly because I had a 8 port moxa box plus a couple of other single cables and regularly a device or two with an inbuilt ftdi chip for usb->serial conversion. Granted I'm an extreme case but given makers / hackers are one of our target audiences I can easily see some of them frequently using more then 4. -- Simon Lees (Simotek) http://simotek.net Emergency Update Team keybase.io/simotek SUSE Linux Adelaide Australia, UTC+10:30 GPG Fingerprint: 5B87 DB9D 88DC F606 E489 CEC5 0922 C246 02F0 014B