Messages in this thread | | | Subject | Re: [PATCH] HID: i2c-hid: Add 60ms delay after SET_POWER ON | From | Hans de Goede <> | Date | Tue, 11 Aug 2020 14:59:33 +0200 |
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Hi,
On 8/11/20 8:00 AM, Kai-Heng Feng wrote: > Hi Hans, > >> On Aug 11, 2020, at 00:13, Hans de Goede <hdegoede@redhat.com> wrote: >> >> Hi, >> >> On 10-08-2020 16:29, Kai-Heng Feng wrote: >>> Goodix touchpad fails to operate in I2C mode after system suspend. >>> According to the vendor, Windows is more forgiving and there's a 60ms >>> delay after SET_POWER ON command. >>> So let's do the same here, to workaround for the touchpads that depend >>> on the delay. >>> Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com> >> >> Interesting I send a very similar patch a couple of days ago, >> after debugging some touchpads issues on a BMAX Y13 laptop: >> >> https://patchwork.kernel.org/patch/11701541/ >> >> If you look at that patch you will see that if we add a >> sleep on power-on to i2c_hid_set_power(), we can remove >> an existing sleep after power-on from i2c_hid_hwreset(). >> >> And there is an interesting comment there which should >> probably be moved (as my patch does) and corrected for the >> new knowledge so that people reading the code in the future >> now why the sleep is there. > > Thanks for the info. > Can you please update your patch with 60ms to supersede mine?
Sure, done.
Regards,
Hans
> >> >> Other then that we've come to the same conclusion, but >> your sleep is much longer. I guess that is ok though, >> are you sure we need 60ms as a minimum? >> Is that what goodix >> said? > > Yes, I was told by Goodix that the 60ms delay is needed. > > Kai-Heng > >> >> Regards, >> >> Hans >> >> >>> --- >>> drivers/hid/i2c-hid/i2c-hid-core.c | 3 +++ >>> 1 file changed, 3 insertions(+) >>> diff --git a/drivers/hid/i2c-hid/i2c-hid-core.c b/drivers/hid/i2c-hid/i2c-hid-core.c >>> index 294c84e136d7..7b24a27fad95 100644 >>> --- a/drivers/hid/i2c-hid/i2c-hid-core.c >>> +++ b/drivers/hid/i2c-hid/i2c-hid-core.c >>> @@ -419,6 +419,9 @@ static int i2c_hid_set_power(struct i2c_client *client, int power_state) >>> if (ret) >>> dev_err(&client->dev, "failed to change power setting.\n"); >>> + if (!ret && power_state == I2C_HID_PWR_ON) >>> + msleep(60); >>> + >>> set_pwr_exit: >>> return ret; >>> } >> >
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