Re: No serial since kernel 3.8

From: Stephan von Krawczynski
Date: Tue Apr 16 2013 - 12:14:46 EST


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?

--
Regards,
Stephan

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