Messages in this thread | | | From | Shenwei Wang <> | Subject | RE: [PATCH v9 1/1] irqchip: imx-gpcv2: IMX GPCv2 driver for wakeup sources | Date | Tue, 25 Aug 2015 19:24:28 +0000 |
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> -----Original Message----- > From: Sudeep Holla [mailto:sudeep.holla@arm.com] > Sent: 2015年8月25日 11:24 > To: Wang Shenwei-B38339 > Cc: Sudeep Holla; shawn.guo@linaro.org; tglx@linutronix.de; > jason@lakedaemon.net; Huang Yongcai-B20788; linux-kernel@vger.kernel.org; > linux-arm-kernel@lists.infradead.org > Subject: Re: [PATCH v9 1/1] irqchip: imx-gpcv2: IMX GPCv2 driver for wakeup > > > > You don't really understand what happens after a driver calls > > enable_irq_wake. In suspend state, even the interrupt controller > > itself is powered off. How can you get the system up again by just > > using a SKIP_SET_WAKE. > > > > Sorry for that, let me try to understand aloud. So you have irq_{un,}mask function > that are called when interrupts are enabled and disabled. So suppose you have 3 > irqs that are enabled and only one of then is set as wakeup source. > > Now you call enable_irq_wake, you save that in wakeup_sources, fine. > Later when you enter suspend, you save all the 3 active irqs in saved_irq_mask > and over-write cpu2wakeup with wakeup_sources, right? > > All fine, what I am saying is let irq-core know that you want to mask the 2 > non-wakeup irqs you have using MASK_ON_SUSPEND. So when > suspend_device_irqs is called in suspend path, that's done for you automatically > and the cpu2wakeup will have just 1 wakeup enabled which is what you are doing > in suspend callback, right ?
/* * Hardware which has no wakeup source configuration facility * requires that the non wakeup interrupts are masked at the * chip level. The chip implementation indicates that with * IRQCHIP_MASK_ON_SUSPEND. */ if (irq_desc_get_chip(desc)->flags & IRQCHIP_MASK_ON_SUSPEND) mask_irq(desc);
IRQCHIP_MASK_ON_SUSPEND flag is for the hardware that has no wakeup source capability. This GPCv2 block is designed to manage the wakeup source, so the flag does not make any sense.
> Now that it's already done for you, you need not do anything extra and hence just > set SKIP_SET_WAKE to do nothing.
static int set_irq_wake_real(unsigned int irq, unsigned int on) { struct irq_desc *desc = irq_to_desc(irq); int ret = -ENXIO;
if (irq_desc_get_chip(desc)->flags & IRQCHIP_SKIP_SET_WAKE) return 0;
if (desc->irq_data.chip->irq_set_wake) ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on);
return ret; } From the codes above, if a irqchip can not handle the wakeup sources, it can set SKIP flag. This driver is intended to manage the wakeup sources, what's the reason to skip here?
Regards, Shenwei
> Hope this clarifies, sorry if I am still missing to understand something here, but I > don't see anything. Let me know. > > Regards, > Sudeep
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