Re: console issue since 3.6, console=ttyS1 hangs

[Sean Young]

On Fri, Oct 28, 2016 at 02:42:25PM -0500, Nathan Zimmer wrote:
> On Thu, Oct 27, 2016 at 09:19:16PM +0100, Sean Young wrote:
> > On Wed, Oct 26, 2016 at 01:16:16PM -0500, Nathan Zimmer wrote:
> > > On 10/25/2016 03:41 PM, Sean Young wrote:
> > > >On Mon, Oct 24, 2016 at 04:49:25PM -0500, Nathan Zimmer wrote:
> > > >>[    1.565062] serial8250: ttyS1 at I/O 0x2f8 (irq = 3) is a 16550A
> > > >The isa probe driver find the serial port.
> > > >
> > > >>[    1.566453] serial 00:04: pnp_assign_resources, try dependent set 0
> > > >>[    1.567383] serial 00:04:   couldn't assign io 0 (min 0x2f8 max 0x2f8)
> > > >But then decides that the port is already in use (the existing serial driver).
> > > >>[    1.568366] serial 00:04: pnp_assign_resources failed (-16)
> > > >>[    1.569188] serial 00:04: unable to assign resources
> > > >>[    1.569924] serial: probe of 00:04 failed with error -16
> > > >Please try and boot 3.7.0 with "8250.share_irqs=1", maybe it will pick
> > > >irq 3 and it will be happy again, but that is just a guess.
> > > >
> > > >I think I have not fully understood what the failure is. Does the serial
> > > >port not work or does the boot hang? What are the symptoms?
> > > With console=ttyS1 the boot will "hang", sometimes it makes it all the way
> > > through but may take 30 minutes, instead of the 2-4 minutes this box
> > 
> > Where does it hang? Any error messages?
> > 
> 
> Shortly after mounting the root.
> After that I get no more output...
> 
> Here is a failure log from 4.8.

So does the console on the serial port work on 4.8? Also what does 
"cat /proc/interrupts" say with and without my change of ordering the
serial pnp probe before the isa probe?

It could be that the serial driver picking a different irq caused another
driver to be forced to pick another irq which does not work.


Sean