From: Marc Zyngier <marc.zyngier@arm.com>
To: Petr Cvek <petrcvekcz@gmail.com>,
hdegoede@redhat.com, tglx@linutronix.de
Cc: linux-kernel@vger.kernel.org, philipp.zabel@gmail.com
Subject: Re: regression in irq sharing caused by genirq: Use irqd_get_trigger_type to compare the trigger type for shared IRQs
Date: Wed, 8 Nov 2017 13:11:04 +0000 [thread overview]
Message-ID: <7a3a89f5-41ea-6c15-72fc-0f62bf748074@arm.com> (raw)
In-Reply-To: <4a6fb044-68b2-6564-b48d-2a6cefcb4655@arm.com>
On 08/11/17 13:09, Marc Zyngier wrote:
> On 07/11/17 23:41, Petr Cvek wrote:
>> Hello,
>>
>> Commit 382bd4de61827 ("genirq: Use irqd_get_trigger_type to compare the
>> trigger type for shared IRQs") causes a regression for pda-power driver
>> and Magician machine (mach-pxa/magician.c).
>>
>> unsigned int oldtype = irqd_get_trigger_type(&desc->irq_data);
>>
>> ... assert:
>> oldtype == 0 //new code
>> old->flags == 0x83 //old code
>> new->flags & IRQF_TRIGGER_MASK == 3
>>
>> if (!((old->flags & new->flags) & IRQF_SHARED) ||
>> (oldtype != (new->flags & IRQF_TRIGGER_MASK)) ||
>> ((old->flags ^ new->flags) & IRQF_ONESHOT))
>> goto mismatch;
>>
>> The assert shows the new code will trigger the jump for "mismatch" error
>> the old variant of code works fine.
>>
>> The case for Magician machine is specific as the same interrupt line is
>> requested twice from the same driver (pda-power). But it still could
>> point to some hidden problem in the IRQ setup code.
>>
>> I wasn't able to trace the code when desc->irq_data is getting set. The
>> flags values should be (as with old->flags):
>>
>> IRQF_SHARED | IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING
>>
>> It could be a problem with a weird IRQ sharing in magician code, but
>> it's still failing the driver and the start of the charging system.
>>
>> IRQ definition in arch/arm/mach-pxa/magician.c looks like this:
>>
>> static struct resource power_supply_resources[] = {
>> [0] = {
>> .name = "ac",
>> .flags = IORESOURCE_IRQ | IORESOURCE_IRQ_HIGHEDGE |
>> IORESOURCE_IRQ_LOWEDGE,
>> .start = IRQ_MAGICIAN_VBUS,
>> .end = IRQ_MAGICIAN_VBUS,
>> },
>> [1] = {
>> .name = "usb",
>> .flags = IORESOURCE_IRQ | IORESOURCE_IRQ_HIGHEDGE |
>> IORESOURCE_IRQ_LOWEDGE,
>> .start = IRQ_MAGICIAN_VBUS,
>> .end = IRQ_MAGICIAN_VBUS,
>> },
>> };
>>
>> and IRQ requests from drivers/power/supply/pda_power.c look like this:
>>
>> if (ac_irq) {
>> ret = request_irq(ac_irq->start, power_changed_isr,
>> get_irq_flags(ac_irq), ac_irq->name,
>> pda_psy_ac);
>> ...
>> if (usb_irq) {
>> ret = request_irq(usb_irq->start, power_changed_isr,
>> get_irq_flags(usb_irq),
>> usb_irq->name, pda_psy_usb);
>>
>> I could rewrite the part in the magician code so it would use only one
>> interrupt, but it doesn't solve why oldtype == 0 problem.
>
> Yeah, this is a pretty ugly corner case that crops up because we more
> and more assume things like DT, which is going to configure the expected
> trigger type ahead of the interrupt being requested... Of course, PXA is
> not converted to DT, and unlikely to ever be.
>
> Could you please give the following hack a go and let us know if it
> solves your problem? If it does, I'll think of a more generic solution.
>
> Thanks,
>
> M.
>
> diff --git a/drivers/power/supply/pda_power.c b/drivers/power/supply/pda_power.c
> index 922a86787c5c..a32ae240ef7d 100644
> --- a/drivers/power/supply/pda_power.c
> +++ b/drivers/power/supply/pda_power.c
> @@ -24,7 +24,15 @@
>
> static inline unsigned int get_irq_flags(struct resource *res)
> {
> - return IRQF_SHARED | (res->flags & IRQF_TRIGGER_MASK);
> + struct irq_data *d = irq_get_irq_data(res->start);
> + unsigned int trig = res->flags & IRQF_TRIGGER_MASK;
> +
> + BUG_ON(!d);
> +
> + if (!irqd_get_trigger_type(d))
> + irqd_set_trigger_type(trig);
Of course, this should be
irqd_set_trigger_type(d, trig);
> +
> + return IRQF_SHARED | trig;
> }
>
> static struct device *dev;
>
>
M.
--
Jazz is not dead. It just smells funny...
next prev parent reply other threads:[~2017-11-08 13:11 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-07 23:41 regression in irq sharing caused by genirq: Use irqd_get_trigger_type to compare the trigger type for shared IRQs Petr Cvek
2017-11-08 13:09 ` Marc Zyngier
2017-11-08 13:11 ` Marc Zyngier [this message]
2017-11-08 13:35 ` Petr Cvek
2017-11-08 13:55 ` Marc Zyngier
2017-11-09 14:50 ` Marc Zyngier
2017-11-09 16:47 ` Petr Cvek
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