linux-kernel - Re: [PATCH 4/6] arm: mach-omap2: remove "OMAP_DEVICE_NO_IDLE_ON

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Message-ID: <874nf31opn.fsf@linaro.org>
Date:	Thu, 18 Apr 2013 15:03:16 -0700
From:	Kevin Hilman <khilman@...aro.org>
To:	Sourav Poddar <sourav.poddar@...com>
Cc:	<gregkh@...uxfoundation.org>, <tony@...mide.com>,
	<rmk+kernel@....linux.org.uk>, <linux-serial@...r.kernel.org>,
	<linux-omap@...r.kernel.org>, <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 4/6] arm: mach-omap2: remove "OMAP_DEVICE_NO_IDLE_ON_SUSPEND" check

Sourav Poddar <sourav.poddar@...com> writes:

> On Thursday 18 April 2013 11:35 PM, Kevin Hilman wrote:
>> Sourav Poddar<sourav.poddar@...com>  writes:
>>
>>> Remove the "OMAP_DEVICE_NO_IDLE_ON_SUSPEND" check, since UART was the only one making
>>> use of it. Now serial core/driver takes care of the case when "no_console_suspend"
>>> is used in the bootargs and you need to keep the clock enable for console even while suspend.
>>>
>>> Signed-off-by: Sourav Poddar<sourav.poddar@...com>
>> NAK.  This patch will break many things...
>>
>>> ---
>>>   arch/arm/mach-omap2/omap_device.c |    7 +------
>>>   1 files changed, 1 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/arch/arm/mach-omap2/omap_device.c b/arch/arm/mach-omap2/omap_device.c
>>> index 381be7a..d6dce8f 100644
>>> --- a/arch/arm/mach-omap2/omap_device.c
>>> +++ b/arch/arm/mach-omap2/omap_device.c
>>> @@ -620,11 +620,8 @@ static int _od_suspend_noirq(struct device *dev)
>>>   	ret = pm_generic_suspend_noirq(dev);
>>>
>>>   	if (!ret&&  !pm_runtime_status_suspended(dev)) {
>>> -		if (pm_generic_runtime_suspend(dev) == 0) {
>>> -			if (!(od->flags&  OMAP_DEVICE_NO_IDLE_ON_SUSPEND))
>>> -				omap_device_idle(pdev);
>> Why did you remove the omap_device_idle() here?
> This patch is used along with patch3 to get rid of the issue. I posted
> them as a
> seperate patch beacuse of the subject line as one goes under drivers/*
> and the other
> arm/mach-omap2/*..
>
> This check was only valid for UART, and if od->flags is set to the
> "OMAP_DEVICE_NO_IDLE_ON_SUSPEND" flag, then UART will not be idled. 

correct, but *every other device* would be idled (if not already idle.)

> But now, we no longer depend on od->flag value to prevent idling of
> our console UART as the prepare/complete apis will take care of them.

Right, so removing the check on od->flags is fine, but what I asked
about is why you removed the omap_device_idle() call.

Remember that this code is called for *every* omap_device during
suspend, not just UART.

What you did stops *every* device from being idled during suspend.

You didn't read my whole message.  Specifically this part:

>> Note that the check is for when the flag is *not* set, so this patch
>> changes behavior for all the drivers that do not use
>> _NO_IDLE_ON_SUSPEND.  I think that's the opposite of what you intended.

Kevin
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