Red Hat Bugzilla – Bug 143927
CONFIG_SERIAL_8250_NR_UARTS=4 and should be 32
Last modified: 2015-01-04 17:14:33 EST
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Description of problem:
CONFIG_SERIAL_8250_NR_UARTS=4 bby default for the kernel.
I use upto 4 8 port multiport serial cards and they do not function
since UARTS are only 4. The auto detection of the these multiport
cards working fine with redhat 9. If this number is increased
the cards are detected and work. I would hope that others would fine
increasing this value to 32 valuable as well.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1.kernel just does not correctly find the serial ports if set to 4.
I can only second that after spending several hours finding out how
to compile and install a kernel only for changing 4 to 32. It was
working fine in Redhat 8 as well.
I fixed this in CVS on the 1st, which was the same day I did the 2.6.9
update build. Can you test if its fixed there ? If not, it should
definitly be fixed in the 2.6.10 kernel in updates-testing.
I grabbed the 2.6.10 from updates testing.
It "sort" of wored...
Instead of getting serial ports ttyS4-ttyS11 for an 8 port card
ttyS44 - ttyS49
All 8 ports were given just not in the order expected. The ports did work.
Why such an unexpected order?
strange. some udev problem maybe? Harald ?
Dave: udev uses for ttyS* the kernel numbering scheme... no udev
involved directly ... sorry.
$ ls /sys/class/tty/ttyS*/dev
Doesn't this odd numbering scheme get fixed ? It is now in the
current kernel release.
I am using 2.6.10-741FC3 and it still is a crazy numbering scheme.
can you attach the dmesg output please ?
Created attachment 113324 [details]
dmesg showing crazy serial port numbering
An update has been released for Fedora Core 3 (kernel-2.6.12-1.1372_FC3) which
may contain a fix for your problem. Please update to this new kernel, and
report whether or not it fixes your problem.
If you have updated to Fedora Core 4 since this bug was opened, and the problem
still occurs with the latest updates for that release, please change the version
field of this bug to 'fc4'.
I brought this up with the upstream maintainer a while ago. He replied..
"I feel that this is a case where there's nothing that can be done
to satisfy everyone - any assignment scheme is always going to have
issues with someone's setup."
Given that changing this behaviour is quite a deviation from the upstream serial
code, this would have to happen upstream rather than exclusively in Fedora.