Red Hat Bugzilla – Bug 189094
kernel-2.6.16-1.2069_FC4 breaks serial port registration (non-win modem)
Last modified: 2015-01-04 17:26:34 EST
Description of problem:
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1.Upgrade kernel to 2.6.16-1.2069_FC4
3.Kernel is unable to register serial port for modem
Apr 15 18:37:00 freedom kernel: Couldn't register serial port 0000:00:0a.0: -28
Apr 15 20:38:14 freedom kernel: ttyS14 at I/O 0xc000 (irq = 5) is a 16550A
lspci -v -s 00:0a.0
00:0a.0 Communication controller: Agere Systems Venus Modem (V90, 56KFlex)
Subsystem: Actiontec Electronics Inc: Unknown device 0480
Flags: bus master, medium devsel, latency 0, IRQ 5
Memory at ef001000 (32-bit, non-prefetchable) [size=256]
I/O ports at c000 [size=256]
I/O ports at c400 [size=256]
I/O ports at c800 [size=8]
Capabilities: [f8] Power Management version 2
By reverting to kernel-2.6.14-1.1653_FC4 the modem's serial port is registered.
how many serial ports do you have ?
If you boot with 8250.nr_uarts=8 (or however many), does it start working again?