Description of problem: Some time between kernel 3.6.7 and 3.7.3 the 8250.nr_uarts boot option stopped working. The boot option is needed for multi-port serial cards to work. Version-Release number of selected component (if applicable): kernel-3.7.3-101.fc17.x86_64 How reproducible: Always Steps to Reproduce: 1. Add '8250.nr_uarts=16' to /etc/default/grub in GRUB_CMDLINE_LINUX and run grub2-mkconfig to update boot config 2. Boot kernel 3.7.3, then type cat /proc/cmdline to verify that boot option is present and dmesg | grep 16550 to see serial driver header 3. Repeat step 2 with kernel 3.6.7 Actual results: [jennings@www12 ~]$ cat /proc/cmdline BOOT_IMAGE=/boot/vmlinuz-3.7.3-101.fc17.x86_64 root=UUID=42d4d848-ab26-4610-98fc-241b48b8ac8e ro 8250.nr_uarts=16 quiet rhgb [jennings@www12 ~]$ dmesg | grep 16550 [ 0.955931] Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled [jennings@www12 ~]$ Expected results: [jennings@www12 ~]$ cat /proc/cmdline BOOT_IMAGE=/boot/vmlinuz-3.6.7-4.fc17.x86_64 root=UUID=42d4d848-ab26-4610-98fc-241b48b8ac8e ro 8250.nr_uarts=16 quiet rhgb [jennings@www12 ~]$ dmesg | grep 16550 [ 0.941811] Serial: 8250/16550 driver, 16 ports, IRQ sharing enabled [jennings@www12 ~]$ Additional info: This bug affects the stock kernels, though I have only tried x86_64 It is different from #212501 where the problem was caused by the 8250 driver being built as a module - here the 8250 driver is compiled in
I'm bitten by this too: [ 0.000000] Command line: BOOT_IMAGE=/vmlinuz-3.7.9-101.fc17.x86_64 root=/dev /mapper/VolGroup00-LogVol00 ro rd.md=0 rd.dm=0 rd.luks=0 8250.nr_uarts=16 KEYTAB LE=us SYSFONT=ter-116b rhgb rd.lvm.lv=VolGroup00/LogVol01 LANG=en_US.UTF-8 rd.lv m.lv=VolGroup00/LogVol00 [ 1.912723] Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled [ 1.933368] 00:0b: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A [ 1.954248] 0000:05:06.0: ttyS1 at I/O 0xb050 (irq = 21) is a 16550A [ 1.974865] 0000:05:06.0: ttyS2 at I/O 0xb040 (irq = 21) is a 16550A [ 1.995488] 0000:05:06.0: ttyS3 at I/O 0xb030 (irq = 21) is a 16550A [ 1.995687] Couldn't register serial port 0000:05:06.0: -28 lspci -v output: 05:06.0 Serial controller: NetMos Technology PCI 9845 Multi-I/O Controller (rev 01) (prog-if 02 [16550]) Subsystem: LSI Logic / Symbios Logic 0P4S (4 port 16550A serial card) Flags: medium devsel, IRQ 21 I/O ports at b050 [size=8] I/O ports at b040 [size=8] I/O ports at b030 [size=8] I/O ports at b020 [size=8] I/O ports at b010 [size=8] I/O ports at b000 [size=16] Kernel driver in use: serial
OK. I can recreate this here as well. No idea why yet, but I'll look into it.
The driver was renamed to 8250_core in 3.7. If you specify "8250_core.nr_uarts=16" it should work (I tested that locally here).
Yes, it works here as well. Thank you
I worked with upstream to see if we can keep the existing prefix for the options. We wound up with a patch that seems to work, but it is very ugly. Ugly enough that upstream is going to figure out a way to change back to using the 8250. prefix going forward, and deprecating the 8250_core prefix. I've included the patch in F17/F18. The original option names (as well as the 8250_core version) will work with the next update.
For what it's worth, I'd have been happy with simply changing the kernel docs (kernel-parameters.txt) to match reality. This change simply wasn't documented anywhere. Anyway, thanks for doing the legwork on this, but simply using the 8250_core prefix solved my problem!
kernel-3.8.3-101.fc17 has been submitted as an update for Fedora 17. https://admin.fedoraproject.org/updates/kernel-3.8.3-101.fc17
kernel-3.8.3-201.fc18 has been submitted as an update for Fedora 18. https://admin.fedoraproject.org/updates/kernel-3.8.3-201.fc18
Package kernel-3.8.3-201.fc18: * should fix your issue, * was pushed to the Fedora 18 testing repository, * should be available at your local mirror within two days. Update it with: # su -c 'yum update --enablerepo=updates-testing kernel-3.8.3-201.fc18' as soon as you are able to, then reboot. Please go to the following url: https://admin.fedoraproject.org/updates/FEDORA-2013-3893/kernel-3.8.3-201.fc18 then log in and leave karma (feedback).
kernel-3.8.3-201.fc18 has been pushed to the Fedora 18 stable repository. If problems still persist, please make note of it in this bug report.
kernel-3.8.3-103.fc17 has been pushed to the Fedora 17 stable repository. If problems still persist, please make note of it in this bug report.