linux-kernel - Re: [PATCH 4/6] pinctrl: single: Add support for wake-up interrupts

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <5257BB8C.5080001@ti.com>
Date:	Fri, 11 Oct 2013 11:49:16 +0300
From:	Roger Quadros <rogerq@...com>
To:	Tony Lindgren <tony@...mide.com>
CC:	<linux-arm-kernel@...ts.infradead.org>,
	<devicetree@...r.kernel.org>,
	Grygorii Strashko <grygorii.strashko@...com>,
	Linus Walleij <linus.walleij@...aro.org>,
	<linux-kernel@...r.kernel.org>,
	Peter Ujfalusi <peter.ujfalusi@...com>,
	Prakash Manjunathappa <prakash.pm@...com>,
	Haojian Zhuang <haojian.zhuang@...aro.org>,
	Benoît Cousson <bcousson@...libre.com>,
	<linux-omap@...r.kernel.org>
Subject: Re: [PATCH 4/6] pinctrl: single: Add support for wake-up interrupts

On 10/10/2013 07:00 PM, Tony Lindgren wrote:
> * Roger Quadros <rogerq@...com> [131010 06:32]:
>>
>> I tried testing this with the USB EHCI driver, but I'm not getting wake up interrupts
>> while the system is still running and only the EHCI controller is runtime suspended.
>>
>> It seems we need to somehow call _reconfigure_io_chain() to update the daisy chain
>> whenever the pad wakeup_enable bit is changed.
> 
> Sounds like this is on omap3? Have you tried calling pcs_soc->rearm() in the
> pcs_irq_handle() like the comments there suggest? At least for me that keeps
> the wake-up interrupts continuously running on omap3 instead of just idle modes.

Yes it is on OMAP3. I haven't tried with pcs_soc->rearm(). I will give it a try and
let you know.
> 
> Now on omap4, I've noticed the wake up interrupts are on all the time based on tests
> with the serial driver.
>  
>> I think pcs_irq_set_wake() is where need to control system wakeup behaviour for the irq.
>> This is where we should be able to change WAKEUP_EN bit of the pad
>> to enable/disable system wakeup for that pad and also call _reconfigure_io_chain().
> 
> Well the irq_set_wake() should only be needed for suspend and resume. For runtime PM
> the wake-events should be always enabled by default as pointed out by Alan Stern
> a while back.

Right, but we need to update the WAKEUP_EN bit in the pad control register for that
to work, no?. This is something we are not doing in the driver.
>  
>> This would mean that we don't really need to set WAKEUP_EN for the pads in the DTS file.
> 
> Well for runtime PM, we should also do the automatic handling if configured.
> But how to do that best is still open..

I didn't get this part. I was thinking that irq_set_wake() should map directly to WAKEUP_EN
bit for the pin.

cheers,
-roger

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/