Messages in this thread | | | Date | Thu, 15 Dec 2011 08:01:46 -0600 | From | Rob Herring <> | Subject | Re: [PATCH 3/9] irq: convert generic-chip to use irq_domain |
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On 12/15/2011 08:08 AM, Shawn Guo wrote: > On Thu, Dec 15, 2011 at 07:39:37AM -0600, Rob Herring wrote: >> On 12/14/2011 11:55 PM, Shawn Guo wrote: >>> On Thu, Dec 15, 2011 at 01:25:20PM +0800, Shawn Guo wrote: >>>> On Wed, Dec 14, 2011 at 09:28:52AM -0600, Rob Herring wrote: >>>>> From: Rob Herring <rob.herring@calxeda.com> >>>>> >>>>> Add irq domain support to irq generic-chip. This enables users of >>>>> generic-chip to support dynamic irq assignment needed for DT interrupt >>>>> binding. Users must be converted to use irq_data.hwirq for determining >>>>> local interrupt numbers rather than using the Linux irq number. >>>>> >>>>> irq_base is kept for now as there are a few users of it. Once they >>>>> are converted to use the irq domain, it can be removed. >>>>> >>>>> Signed-off-by: Rob Herring <rob.herring@calxeda.com> >>>>> Cc: Thomas Gleixner <tglx@linutronix.de> >>>>> --- >>>> >>>> Tested-by: Shawn Guo <shawn.guo@linaro.org> >>>> >>> Sorry, I have to take that tag back after I correct my test setup. >>> It does not work for imx5 TZIC case, because the following change >>> I suggested before is missed. >>> >>> diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c >>> index eb763f7..2a2aac1 100644 >>> --- a/kernel/irq/irqdomain.c >>> +++ b/kernel/irq/irqdomain.c >>> @@ -39,7 +39,7 @@ void irq_domain_add(struct irq_domain *domain) >>> return; >>> } >>> d->domain = domain; >>> - d->hwirq = hwirq; >>> + d->hwirq = hwirq - domain->hwirq_base; >> >> This is a problem. It entirely defeats the point of hwirq_base and it >> would break the GIC. We need to fix this in the generic irq chip. >> > Actually I do not quite understand why we need to make the following > change all over generic-chip.c. > > - u32 mask = 1 << (d->irq - gc->irq_base); > + u32 mask = 1 << d->hwirq; > > Though d->irq is the Linux irq number, "d->irq - gc->irq_base" is > really just what we need here.
That's assuming a linear mapping between the irq and hwirq. What if we start allocating irq_descs on demand within a domain? Then there would be no way to convert.
Rob
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