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From: Laxman Dewangan <ldewangan@nvidia.com>
To: Wolfram Sang <wsa@the-dreams.de>, Dmitry Osipenko <digetx@gmail.com>
Cc: Thierry Reding <thierry.reding@gmail.com>,
	Jonathan Hunter <jonathanh@nvidia.com>,
	Shardar Shariff Md <smohammed@nvidia.com>,
	<linux-tegra@vger.kernel.org>, <linux-i2c@vger.kernel.org>,
	<linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v1] i2c: tegra: Remove suspend-resume
Date: Wed, 30 May 2018 16:29:45 +0530	[thread overview]
Message-ID: <7b93f6b0-0e09-d8e0-b48e-4ef518c3bd9f@nvidia.com> (raw)
In-Reply-To: <20180529180659.f5s56nstykztvykr@ninjato>



On Tuesday 29 May 2018 11:36 PM, Wolfram Sang wrote:
>>> Our I2C driver is based on the interrupt. So we have converted the
>>> suspend/resume to suspend_noirq and reseume_noirq so that we will not allow the
>>> transfer when system interrupt disabled in downstream.
>>>            SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(tegra_i2c_suspend, tegra_i2c_resume)
>>>
>>> In shutdown path, where interrupt disabled and still need i2c, we use the
>>> bit-bang method via GPIO for i2c transfer.
>> In the current upstream kernel suspend/resume can't be simply moved to the
>> 'noirq' stage because resume invokes tegra_i2c_init() which uses runtime PM and
>> that doesn't work with the IRQ's being disabled. But things do not work even
>> with the tegra_i2c_init() changed to work with the disabled IRQ's, like I wrote
>> above the I2C transfer fails (due to timeout) and a "fix" for that failure was
>> to remove reset_control_assert/deassert from the tegra_i2c_init(). So I'd go for
>> a complete suspend/resume removal for now as it is causes problem.
> Laxman, are you convinced or do you have still objections?
Fine with me. Please add my Ack

Acked-by: Laxman Dewangan <ldewangan@nvidia.com>

  reply	other threads:[~2018-05-30 11:00 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-13 21:13 [PATCH v1] i2c: tegra: Remove suspend-resume Dmitry Osipenko
2018-05-14 11:59 ` Thierry Reding
2018-05-14 12:18   ` Wolfram Sang
2018-05-14 13:03     ` Dmitry Osipenko
2018-05-14 12:21   ` Laxman Dewangan
2018-05-14 12:47     ` Thierry Reding
2018-05-14 12:51     ` Dmitry Osipenko
2018-05-29 18:06       ` Wolfram Sang
2018-05-30 10:59         ` Laxman Dewangan [this message]
2018-05-30 20:18 ` Wolfram Sang
2018-05-30 20:25   ` Wolfram Sang
2018-05-30 22:17     ` Dmitry Osipenko
2018-10-17 13:59 ` Jon Hunter
2018-10-17 14:30   ` Dmitry Osipenko
2018-10-17 19:41     ` Jon Hunter
2018-10-17 20:49       ` Dmitry Osipenko

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