From: Wolfram Sang <wsa-z923LK4zBo2bacvFa/9K2g@public.gmane.org>
To: Jisheng Zhang <jszhang-eYqpPyKDWXRBDgjK7y7TUQ@public.gmane.org>
Cc: mika.westerberg-VuQAYsv1563Yd54FQh9/CA@public.gmane.org,
linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org
Subject: Re: [PATCH v2] i2c: designware: Avoid unnecessary resuming during system suspend
Date: Wed, 3 Jun 2015 02:55:33 +0900 [thread overview]
Message-ID: <20150602175532.GD1494@katana> (raw)
In-Reply-To: <1432132393-693-1-git-send-email-jszhang-eYqpPyKDWXRBDgjK7y7TUQ@public.gmane.org>
[-- Attachment #1: Type: text/plain, Size: 1059 bytes --]
On Wed, May 20, 2015 at 10:33:13PM +0800, Jisheng Zhang wrote:
> Commit 1fc2fe204cb9 ("i2c: designware: Add runtime PM hooks") adds
> runtime pm support using the same ops for system pm and runtime pm.
> When suspend to ram, the i2c host may have been runtime suspended, thus
> i2c_dw_disable() hangs.
>
> Previously, I fixed this issue by separating ops for system pm and
> runtime pm, then in the system suspend/resume path, runtime pm apis are
> used to ensure the device is at correct state.
>
> But as Mika Westerberg pointed out: it sounds a bit silly to resume the
> device just because you want to call i2c_dw_disable() for it before
> suspending again. He then suggested an elegant solution which keeps the
> device runtime suspended during system suspend with the help of
> 'dev->power.direct_complete'. This patch adopted this solution, and in
> fact Mika provided the main code.
>
> Signed-off-by: Jisheng Zhang <jszhang-eYqpPyKDWXRBDgjK7y7TUQ@public.gmane.org>
Fixed the 80 char thingie and applied to for-next, thanks!
[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 819 bytes --]
prev parent reply other threads:[~2015-06-02 17:55 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-05-20 14:33 [PATCH v2] i2c: designware: Avoid unnecessary resuming during system suspend Jisheng Zhang
2015-05-21 11:40 ` Mika Westerberg
2015-05-25 2:42 ` Jisheng Zhang
[not found] ` <1432132393-693-1-git-send-email-jszhang-eYqpPyKDWXRBDgjK7y7TUQ@public.gmane.org>
2015-06-02 17:55 ` Wolfram Sang [this message]
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=20150602175532.GD1494@katana \
--to=wsa-z923lk4zbo2bacvfa/9k2g@public.gmane.org \
--cc=jszhang-eYqpPyKDWXRBDgjK7y7TUQ@public.gmane.org \
--cc=linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org \
--cc=linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
--cc=linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
--cc=mika.westerberg-VuQAYsv1563Yd54FQh9/CA@public.gmane.org \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).