> On Oct 3, 2018, at 5:10 PM, Jiri Kosina <jikos@xxxxxxxxxx> wrote: > > 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, I am working on a better approach for this issue, I’ll send a v2 soon. Kai-Heng > > -- > Jiri Kosina > SUSE Labs >
