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Groups > linux.kernel > #1444393
| From | Jason Cooper <jason@lakedaemon.net> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH v2 02/10] irqchip: add irqchip driver for nuc900 |
| Date | 2016-07-15 17:50 +0200 |
| Message-ID | <rVdxf-dW-7@gated-at.bofh.it> (permalink) |
| References | <rThlD-5X6-3@gated-at.bofh.it> <rUPlf-1Xp-7@gated-at.bofh.it> <rV3Hz-2Ms-3@gated-at.bofh.it> <rV5q1-3U6-1@gated-at.bofh.it> <rV7UR-5ff-5@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Fri, Jul 15, 2016 at 05:44:50PM +0800, Wan ZongShun wrote:
> 2016-07-15 15:00 GMT+08:00 Arnd Bergmann <arnd@arndb.de>:
> > On Friday, July 15, 2016 1:15:58 PM CEST Wan Zongshun wrote:
> >>
> >> Actually, I have two choice to implement this function:
> >>
> >> option1:
> >>
> >> void __exception_irq_entry aic_handle_irq(struct pt_regs *regs)
> >> {
> >> u32 hwirq;
> >>
> >> (void)readl(aic_base + REG_AIC_IPER);
> >> hwirq = readl(aic_base + REG_AIC_ISNR);
> >>
> >> handle_IRQ((irq_find_mapping(aic_domain, hwirq)), regs);
> >> }
> >
> > (side note: I think you want handle_domain_irq())
> >
> >> option2:
> >>
> >> void __exception_irq_entry aic_handle_irq(struct pt_regs *regs)
> >> {
> >> u32 hwirq;
> >>
> >> hwirq = readl(aic_base + REG_AIC_IPER);
> >> hwirq <<= 2;
> >>
> >> handle_IRQ((irq_find_mapping(aic_domain, hwirq)), regs);
> >> }
> >>
> >> Though the option2 do shift for hwirq, but it seems better than do io
> >> operation by readl,so I prefer to option2, agree?
> >
> > That will only return an irq number that is a multiple of four, which
> > seems wrong since the numbers are not that. Did you mean to write
> >
> > hwirq = ilog2(hwirq); ?
>
> Sorry, my fault, I mean hwirq >>= 2, bit[7:2] indicates which irq is triggering.
> so I have to do right shift 2 for IPER value.
Ok, this makes a lot more sense now. :)
> > That assumes that REG_AIC_IPER contains a 32-bit value with one single
> > bit set to indicate which IRQ was triggered.
> >
> > If the difference is only in performance, you could try measuring which
> > of the two ends up being faster.
>
> It seems hard to measure. I think Do IO operation should be slower
> than shift 2. :)
Agreed.
thx,
Jason.
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[PATCH v2 00/10] ARM: NUC900: Add NUC970 SoC support Wan Zongshun <vw@iommu.org> - 2016-07-10 09:30 +0200
[PATCH v2 01/10] ARM: NUC900: Add nuc970 machine support Wan Zongshun <vw@iommu.org> - 2016-07-10 09:30 +0200
Re: [PATCH v2 01/10] ARM: NUC900: Add nuc970 machine support Arnd Bergmann <arnd@arndb.de> - 2016-07-11 00:10 +0200
Re: [PATCH v2 01/10] ARM: NUC900: Add nuc970 machine support Arnd Bergmann <arnd@arndb.de> - 2016-07-11 18:10 +0200
Re: [PATCH v2 01/10] ARM: NUC900: Add nuc970 machine support Wan Zongshun <vw@iommu.org> - 2016-07-12 06:40 +0200
Re: [PATCH v2 01/10] ARM: NUC900: Add nuc970 machine support Wan Zongshun <vw@iommu.org> - 2016-07-12 09:20 +0200
Re: [PATCH v2 01/10] ARM: NUC900: Add nuc970 machine support Arnd Bergmann <arnd@arndb.de> - 2016-07-12 10:30 +0200
[PATCH v2 03/10] Clocksource: add nuc970 clocksource driver Wan Zongshun <vw@iommu.org> - 2016-07-10 09:30 +0200
Re: [PATCH v2 03/10] Clocksource: add nuc970 clocksource driver Arnd Bergmann <arnd@arndb.de> - 2016-07-11 17:40 +0200
Re: [PATCH v2 03/10] Clocksource: add nuc970 clocksource driver Wan Zongshun <vw@iommu.org> - 2016-07-12 09:40 +0200
Re: [PATCH v2 03/10] Clocksource: add nuc970 clocksource driver Arnd Bergmann <arnd@arndb.de> - 2016-07-12 10:30 +0200
Re: [PATCH v2 03/10] Clocksource: add nuc970 clocksource driver Arnd Bergmann <arnd@arndb.de> - 2016-07-21 15:00 +0200
Re: [PATCH v2 03/10] Clocksource: add nuc970 clocksource driver Daniel Lezcano <daniel.lezcano@linaro.org> - 2016-07-21 15:00 +0200
[PATCH v2 02/10] irqchip: add irqchip driver for nuc900 Wan Zongshun <vw@iommu.org> - 2016-07-10 09:30 +0200
Re: [PATCH v2 02/10] irqchip: add irqchip driver for nuc900 Paul Gortmaker <paul.gortmaker@windriver.com> - 2016-07-11 00:00 +0200
Re: [PATCH v2 02/10] irqchip: add irqchip driver for nuc900 Wan Zongshun <vw@iommu.org> - 2016-07-11 04:20 +0200
Re: [PATCH v2 02/10] irqchip: add irqchip driver for nuc900 Arnd Bergmann <arnd@arndb.de> - 2016-07-11 17:50 +0200
Re: [PATCH v2 02/10] irqchip: add irqchip driver for nuc900 Wan Zongshun <vw@iommu.org> - 2016-07-12 09:10 +0200
Re: [PATCH v2 02/10] irqchip: add irqchip driver for nuc900 Arnd Bergmann <arnd@arndb.de> - 2016-07-12 10:30 +0200
Re: [PATCH v2 02/10] irqchip: add irqchip driver for nuc900 Wan Zongshun <vw@iommu.org> - 2016-07-14 11:00 +0200
Re: [PATCH v2 02/10] irqchip: add irqchip driver for nuc900 Arnd Bergmann <arnd@arndb.de> - 2016-07-14 13:20 +0200
Re: [PATCH v2 02/10] irqchip: add irqchip driver for nuc900 Jason Cooper <jason@lakedaemon.net> - 2016-07-13 22:10 +0200
Re: [PATCH v2 02/10] irqchip: add irqchip driver for nuc900 Wan Zongshun <vw@iommu.org> - 2016-07-14 05:40 +0200
Re: [PATCH v2 02/10] irqchip: add irqchip driver for nuc900 Jason Cooper <jason@lakedaemon.net> - 2016-07-14 16:00 +0200
Re: [PATCH v2 02/10] irqchip: add irqchip driver for nuc900 Wan Zongshun <vw@iommu.org> - 2016-07-15 07:20 +0200
Re: [PATCH v2 02/10] irqchip: add irqchip driver for nuc900 Arnd Bergmann <arnd@arndb.de> - 2016-07-15 09:10 +0200
Re: [PATCH v2 02/10] irqchip: add irqchip driver for nuc900 Wan ZongShun <mcuos.com@gmail.com> - 2016-07-15 11:50 +0200
Re: [PATCH v2 02/10] irqchip: add irqchip driver for nuc900 Jason Cooper <jason@lakedaemon.net> - 2016-07-15 17:50 +0200
Re: [PATCH v2 02/10] irqchip: add irqchip driver for nuc900 Arnd Bergmann <arnd@arndb.de> - 2016-07-21 13:00 +0200
Re: [PATCH v2 02/10] irqchip: add irqchip driver for nuc900 Jason Cooper <jason@lakedaemon.net> - 2016-07-21 20:50 +0200
Re: [PATCH v2 04/10] clk: add Clock driver for nuc970 Michael Turquette <mturquette@baylibre.com> - 2016-07-12 00:20 +0200
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