From: slash.tmp@free•fr (Mason)
To: linux-arm-kernel@lists•infradead.org
Subject: schedule_timeout sleeps too long after dividing CPU frequency
Date: Wed, 20 May 2015 22:41:33 +0200 [thread overview]
Message-ID: <555CF17D.4060500@free.fr> (raw)
In-Reply-To: <20150520201438.GW2067@n2100.arm.linux.org.uk>
On 20/05/2015 22:14, Russell King - ARM Linux wrote:
> On Wed, May 20, 2015 at 09:34:16PM +0200, Mason wrote:
>> On 20/05/2015 20:50, Arnd Bergmann wrote:
>>>> diff --git a/arch/arm/kernel/smp_twd.c b/arch/arm/kernel/smp_twd.c
>>>> index 6591e26..300f13a 100644
>>>> --- a/arch/arm/kernel/smp_twd.c
>>>> +++ b/arch/arm/kernel/smp_twd.c
>>>> @@ -295,6 +295,10 @@ static void twd_timer_setup(void)
>>>> clk->name = "local_timer";
>>>> clk->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT |
>>>> CLOCK_EVT_FEAT_C3STOP;
>>>> +#ifdef CONFIG_TANGOX
>>>> + /*** Tango does not implement low power modes ***/
>>>> + clk->features &= ~CLOCK_EVT_FEAT_C3STOP;
>>>> +#endif
>>>> clk->rating = 350;
>>>> clk->set_mode = twd_set_mode;
>>>> clk->set_next_event = twd_set_next_event;
>>>
>>> This will disable the feature on all machines that are configured
>>> in the kernel.
>>
>> What do you mean, "disable the feature"?
>>
>> My proposed patch doesn't change the default, which is to set
>> CLOCK_EVT_FEAT_C3STOP unconditionally for all machines.
>>
>> And then only for some platforms (in this case only TANGOX)
>> CLOCK_EVT_FEAT_C3STOP is *removed* from the features list.
>
> So we build a kernel containing both tangox and OMAP together, and
> OMAP starts misbehaving because CLOCK_EVT_FEAT_C3STOP is no longer
> set. That's a regression caused by your change, even if you didn't
> intend for anyone else to enable your option.
Oh... I didn't even think it made sense (and was supported)
to select more than one machine...
Is this related to CONFIG_ARCH_MULTIPLATFORM?
Regards.
next prev parent reply other threads:[~2015-05-20 20:41 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-05-12 14:32 schedule_timeout sleeps too long after dividing CPU frequency Mason
2015-05-12 14:46 ` Viresh Kumar
2015-05-12 15:14 ` Mason
2015-05-12 15:50 ` Russell King - ARM Linux
2015-05-12 16:14 ` Mason
2015-05-13 16:51 ` Mason
2015-05-14 2:13 ` Viresh Kumar
2015-05-14 11:22 ` Mason
2015-05-14 11:54 ` Viresh Kumar
2015-05-14 13:06 ` Mason
2015-05-14 13:53 ` Russell King - ARM Linux
2015-05-14 14:51 ` Mason
2015-05-14 13:59 ` Viresh Kumar
2015-05-14 14:38 ` Viresh Kumar
2015-05-14 14:42 ` Russell King - ARM Linux
2015-05-15 9:29 ` Mason
2015-05-15 9:51 ` Russell King - ARM Linux
2015-05-15 10:01 ` Viresh Kumar
2015-05-15 10:36 ` Mason
2015-05-15 11:58 ` Russell King - ARM Linux
2015-05-15 12:45 ` Mason
2015-05-15 13:15 ` Russell King - ARM Linux
2015-05-15 13:58 ` Mason
2015-05-15 18:35 ` Mason
2015-05-18 11:24 ` Mason
2015-05-18 11:54 ` Russell King - ARM Linux
2015-05-20 16:21 ` Mason
2015-05-20 18:50 ` Arnd Bergmann
2015-05-20 19:34 ` Mason
2015-05-20 20:14 ` Russell King - ARM Linux
2015-05-20 20:41 ` Mason [this message]
2015-05-20 20:52 ` Arnd Bergmann
2015-05-20 21:56 ` Mason
2015-05-20 22:18 ` Arnd Bergmann
2015-05-21 12:35 ` Mason
2015-05-20 23:14 ` Russell King - ARM Linux
2015-05-21 9:56 ` Mason
2015-05-21 10:20 ` Russell King - ARM Linux
2015-05-14 14:48 ` Mason
2015-05-15 4:16 ` Viresh Kumar
2015-05-15 5:07 ` Viresh Kumar
2015-05-15 9:00 ` Russell King - ARM Linux
2015-05-15 9:21 ` Mason
2015-05-15 10:11 ` Mason
2015-05-12 15:23 ` Russell King - ARM Linux
2015-05-12 16:03 ` Mason
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