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From: marc.zyngier@arm•com (Marc Zyngier)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v8 1/4] irqchip: gic: Support hierarchy irq domain.
Date: Tue, 02 Dec 2014 14:12:03 +0000	[thread overview]
Message-ID: <547DC8B3.1000200@arm.com> (raw)
In-Reply-To: <CAMuHMdVkH_qshTfpXBcHx1FiEzL8055s1TiJqayWLXeFUf97NQ@mail.gmail.com>

On 02/12/14 13:55, Geert Uytterhoeven wrote:
> Hi Marc,
> 
> On Tue, Dec 2, 2014 at 2:37 PM, Marc Zyngier <marc.zyngier@arm•com> wrote:
>> On 02/12/14 13:27, Geert Uytterhoeven wrote:
>>> On Tue, Nov 25, 2014 at 9:04 AM, Yingjoe Chen <yingjoe.chen@mediatek•com> wrote:
>>>> Add support to use gic as a parent for stacked irq domain.
>>>>
>>>> Signed-off-by: Yingjoe Chen <yingjoe.chen@mediatek•com>
>>>
>>> This change (which is now in -next as commit 9a1091ef0017c40a) breaks
>>> booting on r8a7740/armadillo-legacy.
>>>
>>> It hangs because the timers cannot get their interrupts:
>>>
>>> console [tty0] enabled
>>>  sh-tmu.0: ch0: used for clock events
>>>  sh-tmu.0: ch0: used for periodic clock events
>>>  sh-tmu.0: ch0: failed to request irq 230
>>>  sh-tmu.0: ch1: used as clock source
>>>  sh-cmt-48.1: ch0: failed to request irq 90
>>>  sh-cmt-48.1: ch0: registration failed
>>> earlytimer: unable to probe sh-cmt-48 early.
>>> Calibrating delay loop...
>>
>> Grmbl... Are you, by any (lack of) chance, using a setup where the GIC
>> is probed via DT, but the timers have their IRQs hardcoded?
> 
> Yes, the GIC is declared in arch/arm/boot/dts/r8a7740.dtsi:
> 
>         gic: interrupt-controller at c2800000 {
>                 compatible = "arm,cortex-a9-gic";
>                 #interrupt-cells = <3>;
>                 interrupt-controller;
>                 reg = <0xc2800000 0x1000>,
>                       <0xc2000000 0x1000>;
>         };
> 
> The timers come from legacy C board code in
> arch/arm/mach-shmobile/setup-r8a7740.c:
> 
> /* CMT */
> static struct sh_timer_config cmt1_platform_data = {
>         .channels_mask = 0x3f,
> };
> 
> static struct resource cmt1_resources[] = {
>         DEFINE_RES_MEM(0xe6138000, 0x170),
>         DEFINE_RES_IRQ(gic_spi(58)),
> };

Yup. This gic_spi() macro is completely doomed, as it computes a
hardware interrupt where the kernel expects a virtual one. The only way
to fix this is to init the GIC outside of DT, so that we stick to a
legacy irqdomain. You can still use information from DT, but you can't
rely on irqchip_init() to produce something that a legacy platform can use.

> The corresponding r8a7740/armadillo-multiplatform works fine.

OK, that's indeed the expected result.

> Still, I'm wondering why sh73a0/kzm9g-legacy is not impacted by this
> change...

I'm a bit lost looking at the shmobile code. But I agree, kzm9g should
die a painful death, as it has the same level of breakage as armadillo.

	M.
-- 
Jazz is not dead. It just smells funny...

  reply	other threads:[~2014-12-02 14:12 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-11-25  8:04 [PATCH v8 0/4] ARM: mediatek: Add support for interrupt polarity Yingjoe Chen
2014-11-25  8:04 ` [PATCH v8 1/4] irqchip: gic: Support hierarchy irq domain Yingjoe Chen
2014-11-25 11:27   ` Marc Zyngier
2014-12-02 13:27   ` Geert Uytterhoeven
2014-12-02 13:37     ` Marc Zyngier
2014-12-02 13:55       ` Geert Uytterhoeven
2014-12-02 14:12         ` Marc Zyngier [this message]
2014-11-25  8:04 ` [PATCH v8 2/4] ARM: mediatek: Add sysirq interrupt polarity support Yingjoe Chen
2014-11-29 17:40   ` Beniamino Galvani
2014-12-01 14:09     ` Yingjoe Chen
2014-11-25  8:04 ` [PATCH v8 3/4] ARM: mediatek: Add sysirq in mt6589/mt8135/mt8127 dtsi Yingjoe Chen
2014-11-27 13:31   ` Yingjoe Chen
2014-12-25  2:11   ` Yingjoe Chen
2015-01-02 10:16     ` Matthias Brugger
2014-11-25  8:04 ` [PATCH v8 4/4] dt-bindings: add bindings for mediatek sysirq Yingjoe Chen
2014-11-26  8:08 ` [PATCH v8 0/4] ARM: mediatek: Add support for interrupt polarity Jason Cooper

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