From mboxrd@z Thu Jan 1 00:00:00 1970 From: adharmap@codeaurora.org (Abhijeet Dharmapurikar) Date: Fri, 31 Dec 2010 02:39:25 -0800 Subject: [PATCH] GIC: Assign correct flow handler type in set_type callback In-Reply-To: References: <1293686960-12581-1-git-send-email-adharmap@codeaurora.org> Message-ID: <4D1DB2DD.3020701@codeaurora.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 12/29/2010 10:27 PM, Rabin Vincent wrote: > On Thu, Dec 30, 2010 at 10:59 AM, Abhijeet Dharmapurikar > 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 >> --- >> 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. But shouldnt set_irq_wake() do something similar? Do I need to request IRQF_NO_SUSPEND for all the interrupts that could possibly wakeup the system - seems a bit unnecessary. IMO the interrupt should not be disabled if it is marked IRQF_NO_SUPEND || IRQ_WAKEUP is set. Abhijeet