Re: [PATCH] video: Fix return value of fb_notifier_call_chain

[Joonyoung Shim]

11/22/2011 08:08 AM, Florian Tobias Schandinat ì ê:
> On 11/21/2011 06:55 AM, Joonyoung Shim wrote:
> > The return value of blocking_notifier_call_chain isn't errno value, it
> > is just notify return value. The ret of fb_notifier_call_chain should is
> > restored to error value from notify return value using
> > notifier_to_errno().
> If I'm not wrong this patch would rather break things than fix them. As I
> understand the notifier_calls would be required to encode the return value with
> notifier_from_errno. This does not happen at the moment for fb clients, for
> example fbcon_event_notify in drivers/video/console/fbcon.c, so this patch would
> screw up the return values, I think.

OK, but it is wrong to return error value than notify value many
callback of fb notify clients and some fb notify clients returns notify
value, please see sh_mobile_lcdc_notify() and sh_hdmi_notify().

We should use only one, notify value or error value, i think it's right
to use notify value.

Thanks.

> Best regards,
>
> Florian Tobias Schandinat
>
> > Signed-off-by: Joonyoung Shim<jy0922.shim@xxxxxxxxxxx>
> > ---
> >   drivers/video/fb_notify.c |    4 +++-
> >   1 files changed, 3 insertions(+), 1 deletions(-)
> >
> > diff --git a/drivers/video/fb_notify.c b/drivers/video/fb_notify.c
> > index 74c2da5..49a64a3 100644
> > --- a/drivers/video/fb_notify.c
> > +++ b/drivers/video/fb_notify.c
> > @@ -42,6 +42,8 @@ EXPORT_SYMBOL(fb_unregister_client);
> >    */
> >   int fb_notifier_call_chain(unsigned long val, void *v)
> >   {
> > -	return blocking_notifier_call_chain(&fb_notifier_list, val, v);
> > +	int ret = blocking_notifier_call_chain(&fb_notifier_list, val, v);
> > +
> > +	return notifier_to_errno(ret);
> >   }
> >   EXPORT_SYMBOL_GPL(fb_notifier_call_chain);

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