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From: David Lechner <david@lechnology.com>
To: Bartosz Golaszewski <brgl@bgdev.pl>, Sekhar Nori <nsekhar@ti.com>,
	Kevin Hilman <khilman@kernel.org>,
	Wolfram Sang <wsa@the-dreams.de>
Cc: linux-arm-kernel@lists.infradead.org, linux-i2c@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	Bartosz Golaszewski <bgolaszewski@baylibre.com>
Subject: Re: [PATCH] i2c: davinci: fix the cpufreq transition
Date: Tue, 23 Jan 2018 21:01:54 -0600	[thread overview]
Message-ID: <dcd94db0-37b0-5a31-6a36-facdf7f58ed3@lechnology.com> (raw)
In-Reply-To: <20180122144258.13627-1-brgl@bgdev.pl>

On 01/22/2018 08:42 AM, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> 
> i2c_davinci_cpufreq_transition() is implemented in a way that will
> block if it ever gets called while no transfer is in progress.
> 
> Not only that, but reinit_completion() is never called for xfr_complete.
> 
> Use the fact that cpufreq uses an srcu_notifier (running in process
> context) for transitions and that the bus_lock is taken during the call
> to master_xfer() and simplify the code by removing the transfer
> completion entirely and protecting i2c_davinci_cpufreq_transition()
> with i2c_lock/unlock_adapter().
> 
> Reported-by: David Lechner <david@lechnology.com>
> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> ---

Tested that it fixes the lockup when there is no active transfer.

Tested-by: David Lechner <david@lechnology.com>

  parent reply	other threads:[~2018-01-24  3:02 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-01-22 14:42 [PATCH] i2c: davinci: fix the cpufreq transition Bartosz Golaszewski
2018-01-23 12:38 ` Sekhar Nori
2018-01-24  3:01 ` David Lechner [this message]
2018-01-24  6:15 ` Wolfram Sang

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