[PATCH 2/3] ARM: GIC: add gic_reinit() function to help ARM resume

[Shawn Guo]

On Tue, Aug 30, 2011 at 10:00:35AM -0500, Rob Herring wrote:
> Shawn,
> 
> On 08/30/2011 02:40 AM, Shawn Guo wrote:
> > If ARM core gets powered off during suspend, GIC controller has to be
> > reinitialized by resume procedure.  This patch adds a helper function
> > for resume procedure to reinitialize GIC.
> 
> Is re-initializing rather than save/restore registers the right thing to
> do here? Won't you lose things like edge or level triggered settings?
> It's always been fuzzy to what should be done with interrupt masks in
> suspend. Is every driver expected to disable and re-enable their
> interrupts or this should be maintained thru a suspend cycle?
> 
Good point.  As one of the series, I easily went for the re-initializing
approach here, plus it is pretty easy to go.  With your reminding, I
agree that for interrupt controller save/restore registers might be the
right thing to do.

> > 
> > Signed-off-by: Shawn Guo <shawn.guo at linaro.org>
> > ---
> >  arch/arm/common/gic.c               |   15 +++++++++++++--
> >  arch/arm/include/asm/hardware/gic.h |    1 +
> >  2 files changed, 14 insertions(+), 2 deletions(-)
> > 
> > diff --git a/arch/arm/common/gic.c b/arch/arm/common/gic.c
> > index 666b278..bf0f6d8 100644
> > --- a/arch/arm/common/gic.c
> > +++ b/arch/arm/common/gic.c
> > @@ -255,7 +255,7 @@ void __init gic_cascade_irq(unsigned int gic_nr, unsigned int irq)
> >  	irq_set_chained_handler(irq, gic_handle_cascade_irq);
> >  }
> >  
> > -static void __init gic_dist_init(struct gic_chip_data *gic,
> > +static void gic_dist_init(struct gic_chip_data *gic,
> >  	unsigned int irq_start)
> >  {
> >  	unsigned int gic_irqs, irq_limit, i;
> > @@ -326,7 +326,7 @@ static void __init gic_dist_init(struct gic_chip_data *gic,
> >  	writel_relaxed(1, base + GIC_DIST_CTRL);
> >  }
> >  
> > -static void __cpuinit gic_cpu_init(struct gic_chip_data *gic)
> > +static void gic_cpu_init(struct gic_chip_data *gic)
> 
> I don't think you need to change this. With hotplug, this section will
> be kept.
> 
You are right.  I missed that it's a __cpuinit.

Regards,
Shawn