On Mon, 1 Oct 2018, Kai-Heng Feng wrote: > Raydium touchpanel (2386:4B33) sometimes does not workin desktop session > although it works in display manager. > > During user logging, the display manager exits, close the HID device, > then the device gets runtime suspended and powered off. The desktop > session begins shortly after, opens the HID device, then the device gets > runtime resumed and powered on. > > If the trasition from display manager to desktop sesesion is fast, the > touchpanel cannot switch from powered off to powered on in short > timeframe. So add a small delay to workaround the issue. > > Signed-off-by: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx> > --- > drivers/hid/i2c-hid/i2c-hid.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/hid/i2c-hid/i2c-hid.c b/drivers/hid/i2c-hid/i2c-hid.c > index f3076659361a..ff5682cc1bce 100644 > --- a/drivers/hid/i2c-hid/i2c-hid.c > +++ b/drivers/hid/i2c-hid/i2c-hid.c > @@ -409,6 +409,8 @@ 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"); > + else > + msleep(20); In case there really is no other way around it, at least please add comment explaining why this ugly msleep() is there. Thanks, -- Jiri Kosina SUSE Labs