From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752525AbdKHNLJ (ORCPT ); Wed, 8 Nov 2017 08:11:09 -0500 Received: from foss.arm.com ([217.140.101.70]:33084 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751789AbdKHNLI (ORCPT ); Wed, 8 Nov 2017 08:11:08 -0500 Subject: Re: regression in irq sharing caused by genirq: Use irqd_get_trigger_type to compare the trigger type for shared IRQs From: Marc Zyngier To: Petr Cvek , hdegoede@redhat.com, tglx@linutronix.de Cc: linux-kernel@vger.kernel.org, philipp.zabel@gmail.com References: <1415e4e2-3ee9-bc31-374c-ba64a506a622@gmail.com> <4a6fb044-68b2-6564-b48d-2a6cefcb4655@arm.com> Organization: ARM Ltd Message-ID: <7a3a89f5-41ea-6c15-72fc-0f62bf748074@arm.com> Date: Wed, 8 Nov 2017 13:11:04 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.4.0 MIME-Version: 1.0 In-Reply-To: <4a6fb044-68b2-6564-b48d-2a6cefcb4655@arm.com> Content-Type: text/plain; charset=iso-8859-2 Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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...