From: t.figa@samsung•com (Tomasz Figa)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v2 4/6] ARM: firmware: add prepare_idle() operation
Date: Fri, 14 Feb 2014 11:42:50 +0100 [thread overview]
Message-ID: <52FDF32A.1040809@samsung.com> (raw)
In-Reply-To: <52FDA6B4.6070404@nvidia.com>
On 14.02.2014 06:16, Alexandre Courbot wrote:
> On 02/13/2014 08:01 PM, Tomasz Figa wrote:
>> Hi Alexandre,
>>
>> On 07.02.2014 05:35, Alexandre Courbot wrote:
>>> Some firmwares do not put the CPU into idle mode themselves, but still
>>> need to be informed that the CPU is about to enter idle mode before this
>>> happens. Add a prepare_idle() operation to the firmware_ops structure to
>>> handle such cases.
>>>
>>> Signed-off-by: Alexandre Courbot <acourbot@nvidia•com>
>>> ---
>>> arch/arm/include/asm/firmware.h | 4 ++++
>>> 1 file changed, 4 insertions(+)
>>
>> I wonder if .do_idle() couldn't simply return an appropriate error code
>> to let the upper layer know that it should proceed with normal CPU idle
>> activation, while still letting the firmware know that the CPU is going
>> to idle.
>
> In our particular case I agree it would be enough to use do_idle() to
> let the firmware know about the operation and have it return -ENOSYS so
> the kernel actually performs it. I'm afraid this might not fulfill all
> needs though (e.g. one can imagine a firmware where the OS needs to take
> action between the notification and the actual shutdown), and as Stephen
> pointed out that would make the name of the function ambiguous at best.
> I'd rather keep it the current way for clarity.
>
OK. I'm not strongly against this, just wanted some more thought on
this, so please move on.
Best regards,
Tomasz
next prev parent reply other threads:[~2014-02-14 10:42 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-02-07 4:35 [PATCH v2 0/6] ARM: firmware: improvements to Trusted Foundations support Alexandre Courbot
2014-02-07 4:35 ` [PATCH v2 1/6] ARM: trusted_foundations: fix vendor prefix typos Alexandre Courbot
2014-02-07 4:35 ` [PATCH v2 2/6] ARM: trusted_foundations: fallback when TF support is missing Alexandre Courbot
2014-02-07 4:35 ` [PATCH v2 3/6] ARM: firmware: enable Trusted Foundations by default Alexandre Courbot
2014-02-07 4:35 ` [PATCH v2 4/6] ARM: firmware: add prepare_idle() operation Alexandre Courbot
2014-02-13 11:01 ` Tomasz Figa
2014-02-13 16:37 ` Stephen Warren
2014-02-14 5:16 ` Alexandre Courbot
2014-02-14 10:42 ` Tomasz Figa [this message]
2014-02-07 4:35 ` [PATCH v2 5/6] ARM: trusted_foundations: implement prepare_idle() Alexandre Courbot
2014-02-07 4:35 ` [PATCH v2 6/6] ARM: tegra: cpuidle: use firmware for power down Alexandre Courbot
2014-02-12 1:36 ` Olof Johansson
2014-02-12 1:56 ` Alexandre Courbot
2014-02-12 2:43 ` [PATCH v3] " Alexandre Courbot
2014-02-12 20:04 ` Olof Johansson
2014-02-12 1:38 ` [PATCH v2 0/6] ARM: firmware: improvements to Trusted Foundations support Olof Johansson
2014-02-12 20:07 ` Stephen Warren
2014-02-18 20:56 ` Stephen Warren
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=52FDF32A.1040809@samsung.com \
--to=t.figa@samsung$(echo .)com \
--cc=linux-arm-kernel@lists$(echo .)infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox