Messages in this thread | | | Date | Sat, 01 Jan 2011 22:26:58 -0800 | From | Abhijeet Dharmapurikar <> | Subject | Re: [PATCH] GIC: Assign correct flow handler type in set_type callback |
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On 12/31/2010 02:39 AM, Abhijeet Dharmapurikar wrote: > On 12/29/2010 10:27 PM, Rabin Vincent wrote: >> On Thu, Dec 30, 2010 at 10:59 AM, Abhijeet Dharmapurikar >> <adharmap@codeaurora.org> wrote: >>> There are some interrupts that are true edge triggered in nature. If not >>> marked IRQ_PENDING, when disabled, they will be lost. >>> >>> Use the set_type callback to assign the correct flow type handler for >>> shared peripheral interrupts. >>> >>> Signed-off-by: Abhijeet Dharmapurikar<adharmap@codeaurora.org> >>> --- >>> This came to light when a edge triggered interrupt was supposed to >>> wakeup the >>> sytem. The flow handler was set to the default handle_level_irq. On >>> the resume >>> path the flow handler was invoked right after the I bit was cleared >>> but before >>> each individual interrupts were enabled. This made the >>> handle_level_irq ignore >> >> Why does the flow handler hit when the interrupt is disabled? Have you >> set >> IRQF_NOSUSPEND on this interrupt? >> > Since GIC doesnt have disable callback it implements lazy disabling. The > interrupt is only marked IRQ_DISABLED in the descriptor but is not > masked in the GIC. Hence the interrupt flow handler is hit. > > Now that I re-read the code setting IRQF_NO_SUSPEND would fix the issue.
Let me correct myself, IRQF_NO_SUSPEND isnt exactly what I want to do. If an interrupt triggers after suspend_device_irqs() is run and before the I bit is set in arch_suspend_disable_irqs() the system will handle the interrupt but will not abort suspend - check_wakeup_irqs() will return 0.
IMO, using handle_edge_irq() for an edge triggered wakeup interrupt would be the right way to address the issue.
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