Re: No serial since kernel 3.8

[Bjorn Helgaas]

[+cc Rafael & linux-acpi]

On Tue, Apr 16, 2013 at 10:14 AM, Stephan von Krawczynski
<skraw@xxxxxxxxxx> wrote:
> On Tue, 16 Apr 2013 10:59:53 -0400
> Josh Boyer <jwboyer@xxxxxxxxx> wrote:
>
>> On Tue, Apr 16, 2013 at 04:55:25PM +0200, richard -rw- weinberger wrote:
>> >On Tue, Apr 16, 2013 at 4:20 PM, Stephan von Krawczynski
>> ><skraw@xxxxxxxxxx> wrote:
>> >> Hello,
>> >>
>> >> can some kind soul please explain how I can get my serial port back under
>> >> kernel 3.8.X. Earlier kernels showed:
>> >>
>> >> Jan 10 13:57:18 mybox kernel: [    0.712829] serial8250: ttyS0 at I/O 0x3f8
>> >> (irq = 4) is a 16550A
>> >>
>> >> But 3.8.4:
>> >>
>> >> Mar 26 10:39:14 admin kernel: [    0.603647] serial 00:0a: disabled
>> >>
>> >> Only kernel is replaced, no change in distro
>> >> Is there some kernel boot parameter needed now?
>> >> I tried 3.4.X and it works, even 3.7.X works...
>> >
>> >So, 3.8.3 worked and 3.8.4 introduced a regression?
>> >If so please confirm.
>> >
>> >CC'ing gregkh, just in case...
>>
>> We had a report of this in Fedora that was fixed with 3.8.7.  An upstream
>> change had been brought back to the 3.8.x series, and it was subsequently
>> reverted.  3.8.7 picked up the revert.
>>
>> josh
>
> 3.8.7 does not work either. I just checked it. I tried shared and not shared IRQ:
>
> Apr 16 17:47:05 mybox kernel: [    0.604826] Serial: 8250/16550 driver, 8 ports, IRQ sharing disabled
>
> and another test:
>
> Apr 16 18:07:08 mybox kernel: [    0.601203] Serial: 8250/16550 driver, 8 ports, IRQ sharing enabled
>
> I must say that 3.8.7 does not even tell the "serial 00:0a: disabled" any more.
> This is no special board, it is a pretty mainstream asus xeon board with onboard serial.
> Loading 3.4.24 (just an example) makes the port work immediately.
> Anything else I can test?

3.7.6 works, and 3.8.3, 3.8.4, 3.8.7 all fail.  So it looks like a
regression between 3.7.6 and 3.8.3.

The "serial 00:0a: disabled" message is from PNP, so I added Rafael
and linux-acpi.  Complete dmesg logs from 3.7.6 and 3.8.4 would be a
place to start.  Also maybe an acpidump, since the 00:0a PNP device
probably came from PNPACPI.  You could attach all these to a
https://bugzilla.kernel.org report if you want a place to stash them.

Josh, do you have a pointer (URL) to the Fedora issue so we can rule
that in or out?

Bjorn
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/