Re: [PATCH] HID: i2c-hid: set power sleep before shutdown

[ghzhong]

On 06/20/2016 05:34 PM, Benjamin Tissoires wrote:
> On Jun 18 2016 or thereabouts, Guohua Zhong wrote:
> > Add i2c_hid_shutdown for i2c-hid driver to send suspend cmd &
> > disable irq before device shutdown.
> >
> > Some HW design is that the power to i2c hid device won't down
> > after device shutdown. Also the i2c-hid driver do not send suspend
> > cmd to the hid i2c device and disable its irq before shutdown.So
> > if We touch the touchscreen or some other i2c hid device ,the power
> > consumtion will be go up even when the device is in shutdown state.
> Wow, that's a new one! Could you tell us which device board is behaving
> that way (if not under NDA or such)
Umaro, a chromebook model.

> > Though the root cause maybe a HW issue. But it seems that it is a
> > good pratice to set power sleep for i2c-hid device before shutdown.
> Works for me:
> Acked-By: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
>
> Cheers,
> Benjamin
>
> > Signed-off-by: Guohua Zhong <ghzhong@xxxxxxxxxxxxxxxxx>
> > ---
> >   drivers/hid/i2c-hid/i2c-hid.c | 8 +++++++-
> >   1 file changed, 7 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/hid/i2c-hid/i2c-hid.c b/drivers/hid/i2c-hid/i2c-hid.c
> > index 2e021ba..d6ea97b 100644
> > --- a/drivers/hid/i2c-hid/i2c-hid.c
> > +++ b/drivers/hid/i2c-hid/i2c-hid.c
> > @@ -1106,6 +1106,12 @@ static int i2c_hid_remove(struct i2c_client *client)
> >   	return 0;
> >   }
> >   
> > +static void i2c_hid_shutdown(struct i2c_client *client)
> > +{
> > +	i2c_hid_set_power(client, I2C_HID_PWR_SLEEP);
> > +	disable_irq(client->irq);
> > +}
> > +
> >   #ifdef CONFIG_PM_SLEEP
> >   static int i2c_hid_suspend(struct device *dev)
> >   {
> > @@ -1230,7 +1236,7 @@ static struct i2c_driver i2c_hid_driver = {
> >   
> >   	.probe		= i2c_hid_probe,
> >   	.remove		= i2c_hid_remove,
> > -
> > +	.shutdown	= i2c_hid_shutdown,
> >   	.id_table	= i2c_hid_id_table,
> >   };
> >   
> > --
> > 1.9.1