On Tue, Jan 15, 2019 at 09:17:58AM +0000, Karoly Pados wrote: > > I think it's better to add the autopm call to gpio210x_gpio_get/set > > only. This will allow for a simpler patch, and keeps the autopm handling > > confined to the gpio paths. > > I'll submit a v2. > > >> @@ -1383,6 +1397,7 @@ static void cp210x_gpio_set(struct gpio_chip *gc, unsigned int gpio, int > >> value) > >> } else { > >> u16 wIndex = buf.state << 8 | buf.mask; > >> > >> + usb_autopm_get_interface(serial->interface); > > > > Also make sure to always check for errors from autopm_get(). > > I checked everywhere else, the reason I didn't check here is on > purpose based on your previous feedback. The caller function here > doesn't have a return value, so the only way to return errors is to > log, but in my last patch to ftdi_sio you made clear that errors from > autopm_get shouldn't get logged. Trying to call usb_control_msg() even > though the device could not wake does not cause issues, and the return > value from usb_control_msg() clearly identifies the reason for failure > (failure due to autosuspend), so error information is not lost either. > So I thought not checking here has no real disadvantage and I still > stay conformant to your previous guidance. Ok, I understand your reasoning, but please do check for errors and bail out early if autopm_get() fails. No need to log errors. Thanks, Johan