[Skiboot] [PATCH] Revert "fsp/console: Allocate irq for each hvc console"

[Alistair Popple]

Hi,

On Wed, 23 Nov 2016 05:03:22 PM Samuel Mendoza-Jonas wrote:
> On Wed, 2016-11-23 at 16:52 +1100, Samuel Mendoza-Jonas wrote:
> > On Tue, 2016-11-22 at 10:49 +0530, Pridhiviraj Paidipeddi wrote:
> > > This reverts commit 583c8203dcb26b42cea81e4734ea926dae05dbb9.
> > 
> > Stewart, please don't merge this yet.
> > Without the patch to add irqs for hvc consoles, we'll get the original
> > lockup problem in Linux 4.2+ that this aimed to solve. We'll need to
> > work out something to make older kernels happy.
> 
> Ah as I page this back into my brain we should be saved by commit fd6b71fc
> which ignores unresponsive consoles (eg. hvc1). Still, without this patch
> host serial will be unusable on Firenze systems.
> 
> > 
> > > 
> > > Below is the WARNING in pre 4.2 linux kernels which is raised in firenze
> > > systems due to interrupts mapping failure.
> > > 
> > > [    0.947741] irq: irq-62==>hwirq-0x3e mapping failed: -22
> > > [    0.947793] ------------[ cut here ]------------
> > > [    0.947838] WARNING: at kernel/irq/irqdomain.c:485
> > > 
> > > So this commit 583c8203dcb26b42cea81e4734ea926dae05dbb9 is causing
> > > the above kernel WARNING(found by git-bisect).
> > > 
> > > Signed-off-by: Pridhiviraj Paidipeddi <ppaidipe at linux.vnet.ibm.com>
> > > ---
> > > -
> > > -		opal_event = dt_find_by_name(opal_node, "event");
> > > -		if (opal_event)
> > > -			dt_add_property_cells(fs_node, "interrupt-parent",
> > > -					      opal_event->phandle);

I think the correct fix is probably just to revert those lines. That should 
avoid the warning but not result in any functional change, although I will 
have to check all the kernel sides.

- Alistair

> > >  	}
> > >  }
> > 
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