From: Chanwoo Choi <cw00.choi@samsung.com>
To: Leonard Crestez <leonard.crestez@nxp.com>,
MyungJoo Ham <myungjoo.ham@samsung.com>
Cc: "Kyungmin Park" <kyungmin.park@samsung.com>,
"Rafael J. Wysocki" <rjw@rjwysocki.net>,
"Matthias Kaehlcke" <mka@chromium.org>,
"Artur Świgoń" <a.swigon@partner.samsung.com>,
"Georgi Djakov" <georgi.djakov@linaro.org>,
"Viresh Kumar" <viresh.kumar@linaro.org>,
linux-pm@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
linux-imx@nxp.com
Subject: Re: [PATCH 1/5] PM / devfreq: Don't fail devfreq_dev_release if not in list
Date: Mon, 2 Dec 2019 10:07:00 +0900 [thread overview]
Message-ID: <8af7ba2c-14eb-fbfa-9fdc-93210c32e65f@samsung.com> (raw)
In-Reply-To: <85684020f25ce186e3383d6bd67a15c54f930316.1573686315.git.leonard.crestez@nxp.com>
On 11/14/19 8:21 AM, Leonard Crestez wrote:
> Right now devfreq_dev_release will print a warning and abort the rest of
> the cleanup if the devfreq instance is not part of the global
> devfreq_list. But this is a valid scenario, for example it can happen if
> the governor can't be found or on any other init error that happens
> after device_register.
>
> Initialize devfreq->node to an empty list head in devfreq_add_device so
> that list_del becomes a safe noop inside devfreq_dev_release and we can
> continue the rest of the cleanup.
>
> Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
> Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
> Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
> ---
> drivers/devfreq/devfreq.c | 6 +-----
> 1 file changed, 1 insertion(+), 5 deletions(-)
>
> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
> index 94fb8e821e12..27af1b95fd23 100644
> --- a/drivers/devfreq/devfreq.c
> +++ b/drivers/devfreq/devfreq.c
> @@ -635,15 +635,10 @@ static int devfreq_notifier_call(struct notifier_block *nb, unsigned long type,
> static void devfreq_dev_release(struct device *dev)
> {
> struct devfreq *devfreq = to_devfreq(dev);
>
> mutex_lock(&devfreq_list_lock);
> - if (IS_ERR(find_device_devfreq(devfreq->dev.parent))) {
> - mutex_unlock(&devfreq_list_lock);
> - dev_warn(&devfreq->dev, "releasing devfreq which doesn't exist\n");
> - return;
> - }
> list_del(&devfreq->node);
> mutex_unlock(&devfreq_list_lock);
>
> if (devfreq->profile->exit)
> devfreq->profile->exit(devfreq->dev.parent);
> @@ -694,10 +689,11 @@ struct devfreq *devfreq_add_device(struct device *dev,
> mutex_init(&devfreq->lock);
> mutex_lock(&devfreq->lock);
> devfreq->dev.parent = dev;
> devfreq->dev.class = devfreq_class;
> devfreq->dev.release = devfreq_dev_release;
> + INIT_LIST_HEAD(&devfreq->node);
> devfreq->profile = profile;
> strncpy(devfreq->governor_name, governor_name, DEVFREQ_NAME_LEN);
> devfreq->previous_freq = profile->initial_freq;
> devfreq->last_status.current_frequency = profile->initial_freq;
> devfreq->data = data;
>
Applied it.
--
Best Regards,
Chanwoo Choi
Samsung Electronics
next prev parent reply other threads:[~2019-12-02 1:00 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-13 23:21 [PATCH 0/5] PM / devfreq: Don't take lock in devfreq_add_device Leonard Crestez
2019-11-13 23:21 ` [PATCH 1/5] PM / devfreq: Don't fail devfreq_dev_release if not in list Leonard Crestez
2019-12-02 1:07 ` Chanwoo Choi [this message]
2019-11-13 23:21 ` [PATCH 2/5] PM / devfreq: Split device_register usage Leonard Crestez
2019-12-02 1:08 ` Chanwoo Choi
2019-12-02 4:45 ` Leonard Crestez
2019-12-02 5:02 ` Chanwoo Choi
2019-11-13 23:21 ` [PATCH 3/5] PM / devfreq: Move more initialization before registration Leonard Crestez
2019-11-13 23:21 ` [PATCH 4/5] PM / devfreq: Don't use devm on parent device Leonard Crestez
2019-11-13 23:21 ` [PATCH 5/5] PM / devfreq: Don't take lock in devfreq_add_device Leonard Crestez
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