> -----Original Message----- > From: ccross@xxxxxxxxxx [mailto:ccross@xxxxxxxxxx] On Behalf Of > Colin Cross > Sent: Wednesday, January 26, 2011 2:25 AM > To: Santosh Shilimkar > Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux- > omap@xxxxxxxxxxxxxxx; catalin.marinas@xxxxxxx; > linux@xxxxxxxxxxxxxxxx; linus.ml.walleij@xxxxxxxxx; Russell King > Subject: Re: [PATCH 1/5] ARM: gic: Add hooks for architecture > specific extensions > > On Mon, Jan 24, 2011 at 7:03 PM, Colin Cross <ccross@xxxxxxxxxxx> > wrote: > > On Mon, Jan 24, 2011 at 12:51 AM, Santosh Shilimkar > > <santosh.shilimkar@xxxxxx> wrote: > >> Few architectures combine the GIC with an external interrupt > controller. > >> On such systems it may be necessary to update both the GIC > registers > >> and the external controller's registers to control IRQ behavior. > >> > >> This can be addressed in couple of possible methods. > >> 1. Export common GIC routines along with 'struct irq_chip > gic_chip' > >> and allow architectures to have custom function by > override. > >> > >> 2. Provide architecture specific function pointer hooks > >> within GIC library and leave platforms to add the > necessary > >> code as part of these hooks. > >> > >> First one might be non-intrusive but have few shortcomings like > arch needs > >> to have there own custom gic library. Locks used should be common > since it > >> caters to same IRQs etc. Maintenance point of view also it leads > to > >> multiple file fixes. > >> > >> The second probably is cleaner and portable. It ensures that all > the > >> common GIC infrastructure is not touched and also provides archs > to > >> address their specific issue. > > > > This method would work for most of Tegra's needs, although we > would > > need gic_set_type and gic_ack_irq to have arch extensions as well. > > However, it does not allow for irq_retrigger, which can be > implemented > > on Tegra. > > irq_retrigger does work with this method, the core IRQ code checks > for > a return value if the retrigger was successful. Tegra works with > your > patch along with these changes: > Great. Can I fold below changes in my patch and add you ack and tested-by? > diff --git a/arch/arm/common/gic.c b/arch/arm/common/gic.c > index 0b6c043..7993f07 100644 > --- a/arch/arm/common/gic.c > +++ b/arch/arm/common/gic.c > @@ -90,6 +90,8 @@ static inline unsigned int gic_irq(struct irq_data > *d) > static void gic_ack_irq(struct irq_data *d) > { > spin_lock(&irq_controller_lock); > + if (gic_arch_extn.irq_ack) > + gic_arch_extn.irq_ack(d); > writel(gic_irq(d), gic_cpu_base(d) + GIC_CPU_EOI); > spin_unlock(&irq_controller_lock); > } > @@ -161,6 +163,14 @@ static int gic_set_type(struct irq_data *d, > unsigned int type) > return 0; > } > > +static int gic_retrigger(struct irq_data *d) > +{ > + if (gic_arch_extn.irq_retrigger) > + return gic_arch_extn.irq_retrigger(d); > + > + return 0; > +} > + > #ifdef CONFIG_SMP > static int > gic_set_cpu(struct irq_data *d, const struct cpumask *mask_val, > bool force) > @@ -234,6 +244,7 @@ static struct irq_chip gic_chip = { > .irq_mask = gic_mask_irq, > .irq_unmask = gic_unmask_irq, > .irq_set_type = gic_set_type, > + .irq_retrigger = gic_retrigger, > #ifdef CONFIG_SMP > .irq_set_affinity = gic_set_cpu, > #endif -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
