Re: [PATCH V2 1/2] tty/hvc: Use IRQF_SHARED for OPAL hvc consoles

[Greg KH <gregkh@linuxfoundation.org>]

On Tue, Jul 26, 2016 at 02:11:11PM +1000, Michael Ellerman wrote:
> Quoting Michael Ellerman (2016-07-11 16:29:20)
> > Samuel Mendoza-Jonas <sam@mendozajonas.com> writes:
> > 
> > > Commit 2def86a7200c
> > > ("hvc: Convert to using interrupts instead of opal events")
> > > enabled the use of interrupts in the hvc_driver for OPAL platforms.
> > > However on machines with more than one hvc console, any console after
> > > the first will fail to register an interrupt handler in
> > > notifier_add_irq() since all consoles share the same IRQ number but do
> > > not set the IRQF_SHARED flag:
> > >
> > > [   51.179907] genirq: Flags mismatch irq 31. 00000000 (hvc_console) vs.
> > > 00000000 (hvc_console)
> > > [   51.180010] hvc_open: request_irq failed with rc -16.
> > >
> > > This error propagates up to hvc_open() and the console is closed, but
> > > OPAL will still generate interrupts that are not handled, leading to
> > > rcu_sched stall warnings.
> > >
> > > Set IRQF_SHARED when calling request_irq, allowing additional consoles
> > > to start properly. This is only set for consoles handled by
> > > hvc_opal_probe(), leaving other types unaffected.
> > >
> > > Signed-off-by: Samuel Mendoza-Jonas <sam@mendozajonas.com>
> > > Cc: <stable@vger.kernel.org> # 4.1.x-
> > > ---
> > >  drivers/tty/hvc/hvc_console.h | 1 +
> > >  drivers/tty/hvc/hvc_irq.c     | 7 +++++--
> > >  drivers/tty/hvc/hvc_opal.c    | 3 +++
> > >  3 files changed, 9 insertions(+), 2 deletions(-)
> > 
> > Acked-by: Michael Ellerman <mpe@ellerman.id.au>
> > 
> > Greg are you happy to take these two?
> 
> Hi Greg,
> 
> I don't see this series anywhere, do you mind if I take them via the
> powerpc tree for 4.8 ? Or do you want to pick them up.

You can take them, I'm not touching patches now until 4.8-rc1 is out,
sorry.

thanks,

greg k-h