lkml.org 
[lkml]   [2019]   [Jan]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] USB: serial: cp210x: Fix GPIO in autosuspend
On Tue, Jan 15, 2019 at 10:26:07AM +0100, Johan Hovold wrote:
> 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.

Actually, we should probably add the missing error handling to the
callers and have gpio_set() propagate errors too. If you want to take a
stab at that, that could be a follow-on patch.

Thanks,
Johan

\
 
 \ /
  Last update: 2019-01-15 11:31    [W:0.059 / U:1.496 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site