All of lore.kernel.org
 help / color / mirror / Atom feed
From: Sudeep Holla <sudeep.holla@arm.com>
To: Daniel Lezcano <daniel.lezcano@linaro.org>,
	"linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org>,
	"linux-arm-kernel@lists.infradead.org"
	<linux-arm-kernel@lists.infradead.org>
Cc: Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com>,
	"Rafael J. Wysocki" <rjw@rjwysocki.net>,
	Sudeep Holla <sudeep.holla@arm.com>
Subject: Re: [PATCH] drivers: cpuidle: don't initialize big.LITTLE driver if MCPM is unavailable
Date: Thu, 08 Jan 2015 14:46:15 +0530	[thread overview]
Message-ID: <54AE4ADF.3030307@arm.com> (raw)
In-Reply-To: <54AE459B.8010703@linaro.org>

Hi Daniel,

On Thursday 08 January 2015 02:23 PM, Daniel Lezcano wrote:
> On 01/08/2015 07:29 AM, Sudeep Holla wrote:
>> If big.LITTLE driver is initialized even when MCPM is unavailable,
>> we get the below warning the first time cpu tries to enter deeper
>> C-states.
>
> Can you elaborate why MCPM could be unavailable when the tc2 pm code
> registers the mcpm platform ops before the cpuidle driver ?
>
>
I can think of 3 possible scenarios. Let me know if these make sense.

1. If the firmware settings in Vexpress configuration files are set to
    boot in legacy mode, but MCPM is enabled in the kernel.
2. If some failure occurs during MCPM initialization
3. For example, if CCI is not accessible as in some Exynos boards [1],
    we don't want to wait till mpcm_cpu_suspend ?

Regards,
Sudeep

[1] 
https://www.mail-archive.com/linux-samsung-soc@vger.kernel.org/msg39624.html

WARNING: multiple messages have this Message-ID (diff)
From: sudeep.holla@arm.com (Sudeep Holla)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] drivers: cpuidle: don't initialize big.LITTLE driver if MCPM is unavailable
Date: Thu, 08 Jan 2015 14:46:15 +0530	[thread overview]
Message-ID: <54AE4ADF.3030307@arm.com> (raw)
In-Reply-To: <54AE459B.8010703@linaro.org>

Hi Daniel,

On Thursday 08 January 2015 02:23 PM, Daniel Lezcano wrote:
> On 01/08/2015 07:29 AM, Sudeep Holla wrote:
>> If big.LITTLE driver is initialized even when MCPM is unavailable,
>> we get the below warning the first time cpu tries to enter deeper
>> C-states.
>
> Can you elaborate why MCPM could be unavailable when the tc2 pm code
> registers the mcpm platform ops before the cpuidle driver ?
>
>
I can think of 3 possible scenarios. Let me know if these make sense.

1. If the firmware settings in Vexpress configuration files are set to
    boot in legacy mode, but MCPM is enabled in the kernel.
2. If some failure occurs during MCPM initialization
3. For example, if CCI is not accessible as in some Exynos boards [1],
    we don't want to wait till mpcm_cpu_suspend ?

Regards,
Sudeep

[1] 
https://www.mail-archive.com/linux-samsung-soc at vger.kernel.org/msg39624.html

  reply	other threads:[~2015-01-08  9:16 UTC|newest]

Thread overview: 29+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-01-08  6:29 [PATCH] drivers: cpuidle: don't initialize big.LITTLE driver if MCPM is unavailable Sudeep Holla
2015-01-08  6:29 ` Sudeep Holla
2015-01-08  8:53 ` Daniel Lezcano
2015-01-08  8:53   ` Daniel Lezcano
2015-01-08  9:16   ` Sudeep Holla [this message]
2015-01-08  9:16     ` Sudeep Holla
2015-01-08 10:02     ` Daniel Lezcano
2015-01-08 10:02       ` Daniel Lezcano
2015-01-08 10:31       ` Sudeep Holla
2015-01-08 10:31         ` Sudeep Holla
2015-01-08 11:11         ` Daniel Lezcano
2015-01-08 11:11           ` Daniel Lezcano
2015-01-08 12:29           ` Lorenzo Pieralisi
2015-01-08 12:29             ` Lorenzo Pieralisi
2015-01-08 14:01             ` Daniel Lezcano
2015-01-08 14:01               ` Daniel Lezcano
2015-01-08 14:46               ` Lorenzo Pieralisi
2015-01-08 14:46                 ` Lorenzo Pieralisi
2015-01-08 20:27             ` Kevin Hilman
2015-01-08 20:27               ` Kevin Hilman
2015-01-08 20:51               ` Daniel Lezcano
2015-01-08 20:51                 ` Daniel Lezcano
2015-01-09 17:34                 ` Kevin Hilman
2015-01-09 17:34                   ` Kevin Hilman
2015-01-09  4:58               ` Sudeep Holla
2015-01-09  4:58                 ` Sudeep Holla
2015-01-09  5:01             ` Sudeep Holla
2015-01-09  5:01               ` Sudeep Holla
  -- strict thread matches above, loose matches on Subject: below --
2015-01-25 14:39 [GIT PULL] : cpuidle-big.little fix when mcpm is not available Daniel Lezcano
2015-01-25 20:53 ` [PATCH] drivers: cpuidle: Don't initialize big.LITTLE driver if MCPM is unavailable Daniel Lezcano

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=54AE4ADF.3030307@arm.com \
    --to=sudeep.holla@arm.com \
    --cc=Lorenzo.Pieralisi@arm.com \
    --cc=daniel.lezcano@linaro.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-pm@vger.kernel.org \
    --cc=rjw@rjwysocki.net \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.