From: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
To: "Vokáč Michal" <Michal.Vokac@ysoft.com>
Cc: "Mark Rutland" <mark.rutland@arm.com>,
"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
"linux-pwm@vger.kernel.org" <linux-pwm@vger.kernel.org>,
"Lukasz Majewski" <l.majewski@majess.pl>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"Rob Herring" <robh+dt@kernel.org>,
"Thierry Reding" <thierry.reding@gmail.com>,
"kernel@pengutronix.de" <kernel@pengutronix.de>,
"Fabio Estevam" <fabio.estevam@nxp.com>,
"Lothar Waßmann" <LW@karo-electronics.de>
Subject: Re: [RCF PATCH,v2,2/2] pwm: imx: Configure output to GPIO in disabled state
Date: Sun, 14 Oct 2018 22:24:57 +0200 [thread overview]
Message-ID: <20181014202457.dohwgz3frgcpdpy6@pengutronix.de> (raw)
In-Reply-To: <20181012160854.hmgpokxgsrqdzobx@pengutronix.de>
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/ |
next prev parent reply other threads:[~2018-10-14 20:25 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-10 9:33 [RCF PATCH v2 0/2] pwm: imx: Configure output to GPIO in disabled state Vokáč Michal
2018-10-10 9:33 ` [RCF PATCH v2 1/2] dt-bindings: pwm: imx: Allow switching PWM output between PWM and GPIO Vokáč Michal
2018-10-10 13:39 ` Thierry Reding
2018-10-29 15:52 ` Vokáč Michal
2018-10-10 9:33 ` [RCF PATCH v2 2/2] pwm: imx: Configure output to GPIO in disabled state Vokáč Michal
2018-10-12 8:57 ` [RCF PATCH,v2,2/2] " Uwe Kleine-König
2018-10-12 15:04 ` Vokáč Michal
2018-10-12 15:54 ` Thierry Reding
2018-10-12 16:08 ` Uwe Kleine-König
2018-10-14 20:24 ` Uwe Kleine-König [this message]
2018-10-15 8:45 ` Thierry Reding
2018-10-29 15:55 ` Vokáč Michal
2018-10-29 15:54 ` Vokáč Michal
2018-11-07 9:33 ` Uwe Kleine-König
2018-11-07 13:32 ` Vokáč Michal
2018-11-07 15:01 ` Uwe Kleine-König
2018-11-08 15:21 ` Vokáč Michal
2018-11-08 19:18 ` Uwe Kleine-König
2018-11-09 14:24 ` Vokáč Michal
2018-11-09 16:55 ` Uwe Kleine-König
2018-11-14 9:09 ` Uwe Kleine-König
2018-11-14 11:34 ` Thierry Reding
2018-11-14 21:51 ` Uwe Kleine-König
2018-11-15 15:25 ` Thierry Reding
2018-11-15 20:37 ` Uwe Kleine-König
2018-11-16 7:34 ` Lothar Waßmann
2018-11-16 8:25 ` Uwe Kleine-König
2018-11-22 15:42 ` Vokáč Michal
2018-11-22 16:23 ` Uwe Kleine-König
2018-11-22 16:46 ` Vokáč Michal
2018-11-22 19:03 ` Uwe Kleine-König
2018-11-23 15:15 ` Vokáč Michal
2018-11-25 20:56 ` Uwe Kleine-König
2018-11-26 9:11 ` Lothar Waßmann
2018-11-26 9:18 ` Uwe Kleine-König
2018-11-26 10:03 ` Lothar Waßmann
2018-11-26 11:51 ` Thierry Reding
2018-11-26 12:23 ` Lothar Waßmann
2018-11-26 13:34 ` Thierry Reding
2018-11-26 15:50 ` Vokáč Michal
2018-11-16 9:51 ` Thierry Reding
2018-11-16 10:39 ` Uwe Kleine-König
2018-11-16 11:56 ` Lothar Waßmann
2018-11-18 11:30 ` Uwe Kleine-König
2018-11-16 12:24 ` Thierry Reding
2018-11-18 20:08 ` Uwe Kleine-König
2018-11-19 8:48 ` Uwe Kleine-König
2018-11-22 15:03 ` Thierry Reding
2018-11-22 16:17 ` Uwe Kleine-König
2018-11-20 13:14 ` Vokáč Michal
2018-11-20 16:54 ` Uwe Kleine-König
2018-11-22 14:23 ` Vokáč Michal
2018-11-19 7:44 ` Linus Walleij
2018-11-19 8:32 ` Uwe Kleine-König
2018-11-20 8:35 ` Linus Walleij
2018-11-20 9:16 ` Viresh Kumar
2018-11-20 9:53 ` Uwe Kleine-König
2018-11-14 11:14 ` Thierry Reding
2018-10-12 16:00 ` [RCF PATCH v2 2/2] " Thierry Reding
2018-10-29 15:53 ` Vokáč Michal
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