Hello,
On Fri, Oct 12, 2018 at 06:08:54PM +0200, Uwe Kleine-König wrote:
> > >> + if (PTR_ERR(imx_chip->pwm_gpiod) == -EPROBE_DEFER) {
> > >
> > > You must not use PTR_ERR on a value that might not contain an error
> > > pointer.
> >
> > OK, thank you for valuable info.
> > So it seems like the I2C folks are in troubles as well:
> >
> >
> > https://elixir.bootlin.com/linux/latest/source/drivers/i2c/busses/i2c-imx.c#L996
>
> correct. I cannot find this documented though.
I found in LDD3[1], chapter 11 on page 295:
If you need the actual error code, it can be extracted with:
long PTR_ERR(const void *ptr);
You should use PTR_ERR only on a value for which IS_ERR returns a true
value; any other value is a valid pointer.
That is probably where I have my claim from. There is no further
explanation though, so I'll post a patch adding a comment to the
definition of PTR_ERR to find out if there is a relevant reason.
Best regards
Uwe
[1] https://lwn.net/Kernel/LDD3/
--
Pengutronix e.K. | Uwe Kleine-König |
Industrial Linux Solutions | http://www.pengutronix.de/ |
