Re: No serial since kernel 3.8

From: Josh Boyer
Date: Wed Apr 17 2013 - 13:49:55 EST


On Wed, Apr 17, 2013 at 11:38:30AM -0600, Bjorn Helgaas wrote:
>[+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?

https://lkml.org/lkml/2013/4/2/426 is the upstream thread. Seems that
was narrowed down to 3.8.4 though, not 3.8.3.

josh
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