Re: [PATCH] HID: i2c-hid: add polling mode based on connected GPIO chip's pin status

[Coiby Xu]

Hi Barnabás,

Thank you for reviewing theis patch! I've Cced a new version to you.

On Thu, Oct 15, 2020 at 10:33:50AM +0000, Barnabás Pőcze wrote:
> Hi,
>
> I believe this patch causes I2C HID devices not to work with IRQs after resuming
> from suspend.
>
>
> > [...]
> >  #ifdef CONFIG_PM_SLEEP
> > @@ -1183,7 +1292,8 @@ static int i2c_hid_suspend(struct device *dev)
> >  	/* Save some power */
> >  	i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
> >
> > -	disable_irq(client->irq);
> > +	if (polling_mode == I2C_POLLING_DISABLED)
> > +		disable_irq(client->irq);
>
> The IRQ is disabled when suspending if polling is *off*.
>
>
> >  	if (device_may_wakeup(&client->dev)) {
> >  		wake_status = enable_irq_wake(client->irq);
> > @@ -1216,7 +1326,7 @@ static int i2c_hid_resume(struct device *dev)
> >
> >  		if (ihid->pdata.post_power_delay_ms)
> >  			msleep(ihid->pdata.post_power_delay_ms);
> > -	} else if (ihid->irq_wake_enabled) {
> > +	} else if (ihid->irq_wake_enabled && polling_mode != I2C_POLLING_DISABLED) {
>
> As a side note, I'm not sure if the 'polling_mode != I2C_POLLING_DISABLED' part
> is necessary (or that it's necessary *here*). It causes 'i2c_hid_resume' and
> 'i2c_hid_suspend' to be "asymmetric" which - I believe - may cause problems.
>
>
> >  		wake_status = disable_irq_wake(client->irq);
> >  		if (!wake_status)
> >  			ihid->irq_wake_enabled = false;
> > @@ -1225,7 +1335,8 @@ static int i2c_hid_resume(struct device *dev)
> >  				wake_status);
> >  	}
> >
> > -	enable_irq(client->irq);
> > +	if (polling_mode != I2C_POLLING_DISABLED)
> > +		enable_irq(client->irq);
>
> The IRQ is enabled when resuming if polling is *on*. It should be enabled if polling is *off*
> in my opinion.
>
>
> > [...]
>
>
> Regards,
> Barnabás Pőcze

--
Best regards,
Coiby