From: Mason <slash.tmp@free.fr>
To: Marc Zyngier <marc.zyngier@arm.com>,
Thomas Gleixner <tglx@linutronix.de>,
Jason Cooper <jason@lakedaemon.net>
Cc: LKML <linux-kernel@vger.kernel.org>,
Linux ARM <linux-arm-kernel@lists.infradead.org>,
Sebastian Frias <sf84@laposte.net>
Subject: Re: Disabling an interrupt in the handler locks the system up
Date: Fri, 21 Oct 2016 20:39:41 +0200 [thread overview]
Message-ID: <580A60ED.3030307@free.fr> (raw)
In-Reply-To: <a79e2d2c-8ec8-744f-50fb-8c39216aa23e@arm.com>
On 21/10/2016 19:46, Marc Zyngier wrote:
> On 21/10/16 17:37, Mason wrote:
>
>> On my platform, one HW block pulls the interrupt line high
>> as long as it remains idle, and low when it is busy.
>>
>> The device tree node is:
>>
>> test@22222 {
>> compatible = "vendor,testme";
>> interrupts = <23 IRQ_TYPE_LEVEL_HIGH>;
>> };
>
> I assume that this is for the sake of the discussion, and that you do
> not actually intend to put together such a monstrosity.
It's just missing a reg properties to be a valid node, right?
>> I wrote a minimal driver which registers the irq.
>> And in the interrupt handler, I disable said irq.
>>
>> Since the irq is IRQ_TYPE_LEVEL_HIGH, it will fire as soon as
>> it is registered (because the block is idle).
>>
>> Here is the code I've been running, request_irq doesn't return.
>
> [...]
>
>> And here's what I get when I try to load the module:
>> (I'm using the default CONFIG_RCU_CPU_STALL_TIMEOUT=21)
>
> [...]
>
>> Are we not supposed to disable the irq in the handler?
>
> You can. It then depends on what your interrupt controller does to
> actually ensure that the interrupt is disabled. Only you can trace it on
> your HW to find out.
I'm using an upstream driver on v4.9-rc1
http://lxr.free-electrons.com/source/drivers/irqchip/irq-tango.c
Given that the system locks up, is it possible there is a bug
in the driver?
Which call-back handles enabling/disabling interrupts?
Regards.
WARNING: multiple messages have this Message-ID (diff)
From: slash.tmp@free.fr (Mason)
To: linux-arm-kernel@lists.infradead.org
Subject: Disabling an interrupt in the handler locks the system up
Date: Fri, 21 Oct 2016 20:39:41 +0200 [thread overview]
Message-ID: <580A60ED.3030307@free.fr> (raw)
In-Reply-To: <a79e2d2c-8ec8-744f-50fb-8c39216aa23e@arm.com>
On 21/10/2016 19:46, Marc Zyngier wrote:
> On 21/10/16 17:37, Mason wrote:
>
>> On my platform, one HW block pulls the interrupt line high
>> as long as it remains idle, and low when it is busy.
>>
>> The device tree node is:
>>
>> test at 22222 {
>> compatible = "vendor,testme";
>> interrupts = <23 IRQ_TYPE_LEVEL_HIGH>;
>> };
>
> I assume that this is for the sake of the discussion, and that you do
> not actually intend to put together such a monstrosity.
It's just missing a reg properties to be a valid node, right?
>> I wrote a minimal driver which registers the irq.
>> And in the interrupt handler, I disable said irq.
>>
>> Since the irq is IRQ_TYPE_LEVEL_HIGH, it will fire as soon as
>> it is registered (because the block is idle).
>>
>> Here is the code I've been running, request_irq doesn't return.
>
> [...]
>
>> And here's what I get when I try to load the module:
>> (I'm using the default CONFIG_RCU_CPU_STALL_TIMEOUT=21)
>
> [...]
>
>> Are we not supposed to disable the irq in the handler?
>
> You can. It then depends on what your interrupt controller does to
> actually ensure that the interrupt is disabled. Only you can trace it on
> your HW to find out.
I'm using an upstream driver on v4.9-rc1
http://lxr.free-electrons.com/source/drivers/irqchip/irq-tango.c
Given that the system locks up, is it possible there is a bug
in the driver?
Which call-back handles enabling/disabling interrupts?
Regards.
next prev parent reply other threads:[~2016-10-21 18:40 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-21 16:37 Disabling an interrupt in the handler locks the system up Mason
2016-10-21 16:37 ` Mason
2016-10-21 17:46 ` Marc Zyngier
2016-10-21 17:46 ` Marc Zyngier
2016-10-21 18:39 ` Mason [this message]
2016-10-21 18:39 ` Mason
2016-10-21 19:14 ` Marc Zyngier
2016-10-21 19:14 ` Marc Zyngier
2016-10-21 19:47 ` Mason
2016-10-21 19:47 ` Mason
2016-10-21 19:49 ` Thomas Gleixner
2016-10-21 19:49 ` Thomas Gleixner
2016-10-21 20:27 ` Mason
2016-10-21 20:27 ` Mason
2016-10-22 11:37 ` Marc Zyngier
2016-10-22 11:37 ` Marc Zyngier
2016-10-22 23:10 ` Mason
2016-10-22 23:10 ` Mason
2016-10-24 8:17 ` Marc Zyngier
2016-10-24 8:17 ` Marc Zyngier
2016-10-24 16:12 ` Mason
2016-10-24 16:12 ` Mason
2016-10-24 16:55 ` Thomas Gleixner
2016-10-24 16:55 ` Thomas Gleixner
2016-10-25 8:29 ` Sebastian Frias
2016-10-25 8:29 ` Sebastian Frias
2016-10-25 8:36 ` Mason
2016-10-25 8:36 ` Mason
2016-10-25 10:45 ` Marc Zyngier
2016-10-25 10:45 ` Marc Zyngier
2016-10-25 13:56 ` Mason
2016-10-25 13:56 ` Mason
2016-10-25 13:56 ` Thomas Gleixner
2016-10-25 13:56 ` Thomas Gleixner
2016-10-25 9:20 ` Thomas Gleixner
2016-10-25 9:20 ` Thomas Gleixner
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