RE: [PATCH] HID: i2c-hid: Add I2C_HID_QUIRK_NO_DELAY_AFTER_PWR_ON to optimize timing

From: Johnny.Chuang
Date: Mon May 17 2021 - 21:07:59 EST


> On Mon, 17 May 2021 at 16:57, Johnny Chuang
> <johnny.chuang.emc@xxxxxxxxx> wrote:
> >
> > There is a hard coding 60ms delay after I2C_HID_PWR_ON commadn.
> > Elan didn't need the delay, so we add a quirk to reduce boot time and
> resume time.
> >
> > Optimized: eef4016243e9("HID: i2c-hid: Always sleep 60ms after
> > I2C_HID_PWR_ON commands")
>
> I don't think Optimized: is a valid commit tag, though I'm not sure if it'll cause
> any problems.

I will change to Fixed tag at PATCH v2.

>
> >
> > Signed-off-by: Johnny Chuang <johnny.chuang.emc@xxxxxxxxx>
> > ---
> > drivers/hid/i2c-hid/i2c-hid-core.c | 9 ++++++++-
> > 1 file changed, 8 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/hid/i2c-hid/i2c-hid-core.c
> > b/drivers/hid/i2c-hid/i2c-hid-core.c
> > index 9993133..e7ec280 100644
> > --- a/drivers/hid/i2c-hid/i2c-hid-core.c
> > +++ b/drivers/hid/i2c-hid/i2c-hid-core.c
> > [...snip...]
> > @@ -178,6 +179,11 @@ static const struct i2c_hid_quirks {
> > I2C_HID_QUIRK_RESET_ON_RESUME },
> > { USB_VENDOR_ID_ITE,
> I2C_DEVICE_ID_ITE_LENOVO_LEGION_Y720,
> > I2C_HID_QUIRK_BAD_INPUT_SIZE },
> > + /*
> > + * Optimize boot time and resume time
> > + */
>
> This comment is a bit too vague to be useful; maybe state that Elan devices
> don't need the delay instead, or just remove the comment.
>
> Other than that,

Okay, I will change to Elan devices don't need the delay at PATCH v2.

>
> Reviewed-by: Harry Cutts <hcutts@xxxxxxxxxxxx>
>
> > + { USB_VENDOR_ID_ELAN, HID_ANY_ID,
> > + I2C_HID_QUIRK_NO_DELAY_AFTER_PWR_ON },
> > { 0, 0 }
> > };
> >
> > @@ -427,7 +433,8 @@ static int i2c_hid_set_power(struct i2c_client *client,
> int power_state)
> > * PWR_ON requests. Testing has confirmed that several devices
> > * will not work properly without a delay after a PWR_ON
> request.
> > */
> > - if (!ret && power_state == I2C_HID_PWR_ON)
> > + if (!ret && power_state == I2C_HID_PWR_ON &&
> > + !(ihid->quirks &
> I2C_HID_QUIRK_NO_DELAY_AFTER_PWR_ON))
> > msleep(60);
> >
> > return ret;
> > --
> > 2.7.4
> >