Re: [PATCH v11 4/8] Input: goodix - add power management support
From: Dmitry Torokhov
Date: Thu Nov 19 2015 - 17:31:20 EST
On Thu, Nov 19, 2015 at 2:18 PM, Rafael J. Wysocki <rafael@xxxxxxxxxx> wrote:
> On Thu, Nov 19, 2015 at 7:24 PM, Dmitry Torokhov
> <dmitry.torokhov@xxxxxxxxx> wrote:
>> On Thu, Nov 19, 2015 at 02:26:37PM +0200, Irina Tirdea wrote:
>>> Implement suspend/resume for goodix driver.
>>> +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
> What exactly do you mean? The suspend watchdog or something else?
I was thinking about dpm watchdog that will panic the system if
suspend takes too long. Hmm, this is debug facility and the default
timeout is 60 seconds, so I guess we can ignore my concern.
>> Rafael, if we issue pm_stay_awake() before requesting firmware and
>> pm_relax() once it is done, will this prevent the current suspend
> pm_stay_awake() only works if the checking of wakeup sources is
> enabled which generally depends on what user space does.
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