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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>

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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!


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      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]

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