Re: [PATCH v2] HID: i2c-hid: Skip ELAN power-on command after reset

[Harry Cutts]

On Mon, 12 Apr 2021 at 10:56, Harry Cutts <hcutts@xxxxxxxxxxxx> wrote:
>
> On Sun, 11 Apr 2021 at 18:21, Johnny Chuang <johnny.chuang.emc@xxxxxxxxx> wrote:
> >
> > Previous commit 43b7029f475e ("HID: i2c-hid:
> > Send power-on command after reset"), it fixed issue for SIS touchscreen.
> >
> > For ELAN touchscreen, we found our boot code of IC was not flexible enough
> > to receive and handle this command.
> > Once the FW main code of our controller is crashed for some reason,
> > the controller could not be enumerated successfully to be recognized
> > by the system host. therefore, it lost touch functionality.
> >
> > Add quirk for skip send power-on command after reset.
> > It will impact to ELAN touchscreen and touchpad on HID over I2C projects.
> >
> > Signed-off-by: Johnny Chuang <johnny.chuang.emc@xxxxxxxxx>
>
> It's probably a good idea to add a Fixes: tag, like so:
>
>     Fixes: 43b7029f475e ("HID: i2c-hid: Send power-on command after reset")
>
> Other than that,
>
> Reviewed-by: Harry Cutts <hcutts@xxxxxxxxxxxx>
>
> Harry Cutts
> Chrome OS Touch/Input team
>
> > ---
> > Changes in v2:
> >     - move comment to quirk entry
> > ---
> >  drivers/hid/i2c-hid/i2c-hid-core.c | 10 +++++++++-
> >  1 file changed, 9 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..957d865 100644
> > --- a/drivers/hid/i2c-hid/i2c-hid-core.c
> > +++ b/drivers/hid/i2c-hid/i2c-hid-core.c
> > @@ -45,6 +45,7 @@
> >  #define I2C_HID_QUIRK_BOGUS_IRQ                        BIT(4)
> >  #define I2C_HID_QUIRK_RESET_ON_RESUME          BIT(5)
> >  #define I2C_HID_QUIRK_BAD_INPUT_SIZE           BIT(6)
> > +#define I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET    BIT(7)
> >
> >
> >  /* flags */
> > @@ -178,6 +179,12 @@ 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 },
> > +/*
> > + * Sending the wakeup after reset actually break ELAN touchscreen controller
> > + * Add I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET to skip wakeup after reset
> > + */

...though, just spotted, you should indent the comment.

> > +       { USB_VENDOR_ID_ELAN, HID_ANY_ID,
> > +                I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET },
> >         { 0, 0 }
> >  };
> >
> > @@ -461,7 +468,8 @@ static int i2c_hid_hwreset(struct i2c_client *client)
> >         }
> >
> >         /* At least some SIS devices need this after reset */
> > -       ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
> > +       if (!(ihid->quirks & I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET))
> > +               ret = i2c_hid_set_power(client, I2C_HID_PWR_ON);
> >
> >  out_unlock:
> >         mutex_unlock(&ihid->reset_lock);
> > --
> > 2.7.4
> >