Re: [PATCH v11 4/8] Input: goodix - add power management support

From: "Rafael J. Wysocki" <rafael@kernel.org>
To: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Irina Tirdea <irina.tirdea@intel.com>,
	"Rafael J. Wysocki" <rafael@kernel.org>,
	Bastien Nocera <hadess@hadess.net>,
	Aleksei Mamlin <mamlinav@gmail.com>,
	Karsten Merker <merker@debian.org>,
	linux-input@vger.kernel.org, Mark Rutland <mark.rutland@arm.com>,
	Rob Herring <robh+dt@kernel.org>,
	Octavian Purdila <octavian.purdila@intel.com>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>
Subject: Re: [PATCH v11 4/8] Input: goodix - add power management support
Date: Thu, 19 Nov 2015 23:18:06 +0100	[thread overview]
Message-ID: <CAJZ5v0iPwohZt+N1quhnCq0zj+HSROaA_8nOTFV_zisYCa2bRw@mail.gmail.com> (raw)
In-Reply-To: <20151119182433.GB24773@dtor-ws>

Hi,

On Thu, Nov 19, 2015 at 7:24 PM, Dmitry Torokhov
<dmitry.torokhov@gmail.com> wrote:
> On Thu, Nov 19, 2015 at 02:26:37PM +0200, Irina Tirdea wrote:
>> Implement suspend/resume for goodix driver.
>>

[cut]

>>
>> +static int __maybe_unused goodix_suspend(struct device *dev)
>> +{
>> +     struct i2c_client *client = to_i2c_client(dev);
>> +     struct goodix_ts_data *ts = i2c_get_clientdata(client);
>> +     int error;
>> +
>> +     /* We need gpio pins to suspend/resume */
>> +     if (!ts->gpiod_int || !ts->gpiod_rst)
>> +             return 0;
>> +
>> +     wait_for_completion(&ts->firmware_loading_complete);
>
> This is not that nice as it may lead to angry splats from the PM core if
> firmware loading takes too long and we start suspending before it
> completes.

What exactly do you mean?  The suspend watchdog or something else?

> Rafael, if we issue pm_stay_awake() before requesting firmware and
> pm_relax() once it is done, will this prevent the current suspend
> timeouts?

pm_stay_awake() only works if the checking of wakeup sources is
enabled which generally depends on what user space does.

Thanks,
Rafael