Re: [PATCH v1 1/1] Input: elantech - fix absolute mode setting on some Asus touchpads

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

Hi Ulrik,

On Wed, Mar 25, 2015 at 10:27:55PM +0100, Ulrik De Bie wrote:
> On Asus TP500LN and X750JN, the touchpad absolute mode is reset each
> time set_rate is done.
> 
> In order to fix this, we will verify the firmware version, and if it
> matches the one in those laptops, the set_rate function is overloaded
> with a function elantech_set_rate_restore_reg_07 that perfoms the
> set_rate with the original function, followed by a restore of reg_07
> (the register that sets the absolute mode on elantech v4 hardware).
> 
> Also the asus TP500LN and X750JN firmware version, capabilities, and
> button constellation is added to elantech.c
> 
> Reported-and-tested-by: George Moutsopoulos <gmoutso@yahoo.co.uk>
> Signed-off-by: Ulrik De Bie <ulrik.debie-os@e2big.org>
> ---
>  drivers/input/mouse/elantech.c | 22 ++++++++++++++++++++++
>  drivers/input/mouse/elantech.h |  1 +
>  2 files changed, 23 insertions(+)
> 
> diff --git a/drivers/input/mouse/elantech.c b/drivers/input/mouse/elantech.c
> index 6e22682..991dc6b 100644
> --- a/drivers/input/mouse/elantech.c
> +++ b/drivers/input/mouse/elantech.c
> @@ -893,6 +893,21 @@ static psmouse_ret_t elantech_process_byte(struct psmouse *psmouse)
>  }
>  
>  /*
> + * This writes the reg_07 value again to the hardware at the end of every
> + * set_rate call because the register loses its value. reg_07 allows setting
> + * absolute mode on v4 hardware
> + */
> +static void elantech_set_rate_restore_reg_07(struct psmouse *psmouse,
> +		unsigned int rate)
> +{
> +	struct elantech_data *etd = psmouse->private;
> +
> +	etd->original_set_rate(psmouse, rate);
> +	if (elantech_write_reg(psmouse, 0x07, etd->reg_07))
> +		psmouse_err(psmouse, "restoring reg_07 failed\n");

I wonder if set rate is useful for Elantech and if it would not be
simpler to just have an empty stub for set_rate, maybe even for all
Elantech devices?

Thanks.

-- 
Dmitry