diff mbox series

[RFC,v1,2/9] pinctrl: devicetree: Delete usage of driver_deferred_probe_check_state()

Message ID 20220526081550.1089805-3-saravanak@google.com
State Accepted
Commit 24a026f85241a01bbcfe1b263caeeaa9a79bab40
Headers show
Series deferred_probe_timeout logic clean up | expand

Commit Message

Saravana Kannan May 26, 2022, 8:15 a.m. UTC
Now that fw_devlink=on by default and fw_devlink supports
"pinctrl-[0-8]" property, the execution will never get to the point
where driver_deferred_probe_check_state() is called before the supplier
has probed successfully or before deferred probe timeout has expired.

So, delete the call and replace it with -ENODEV.

Signed-off-by: Saravana Kannan <saravanak@google.com>
---
 drivers/pinctrl/devicetree.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Geert Uytterhoeven May 30, 2022, 9:22 a.m. UTC | #1
Hi Saravana,

Thanks for your patch!

On Thu, May 26, 2022 at 10:16 AM Saravana Kannan <saravanak@google.com> wrote:
> Now that fw_devlink=on by default and fw_devlink supports
> "pinctrl-[0-8]" property, the execution will never get to the point

0-9?

oh, it's really 0-8:

    drivers/of/property.c:DEFINE_SIMPLE_PROP(pinctrl0, "pinctrl-0", NULL)
    drivers/of/property.c:DEFINE_SIMPLE_PROP(pinctrl1, "pinctrl-1", NULL)
    drivers/of/property.c:DEFINE_SIMPLE_PROP(pinctrl2, "pinctrl-2", NULL)
    drivers/of/property.c:DEFINE_SIMPLE_PROP(pinctrl3, "pinctrl-3", NULL)
    drivers/of/property.c:DEFINE_SIMPLE_PROP(pinctrl4, "pinctrl-4", NULL)
    drivers/of/property.c:DEFINE_SIMPLE_PROP(pinctrl5, "pinctrl-5", NULL)
    drivers/of/property.c:DEFINE_SIMPLE_PROP(pinctrl6, "pinctrl-6", NULL)
    drivers/of/property.c:DEFINE_SIMPLE_PROP(pinctrl7, "pinctrl-7", NULL)
    drivers/of/property.c:DEFINE_SIMPLE_PROP(pinctrl8, "pinctrl-8", NULL)

Looks fragile, especially since we now have:

    arch/arm64/boot/dts/microchip/sparx5_pcb134_board.dtsi:
pinctrl-9 = <&i2cmux_9>;
    arch/arm64/boot/dts/microchip/sparx5_pcb134_board.dtsi: pinctrl-10
= <&i2cmux_10>;
    arch/arm64/boot/dts/microchip/sparx5_pcb134_board.dtsi: pinctrl-11
= <&i2cmux_11>;
    arch/arm64/boot/dts/microchip/sparx5_pcb134_board.dtsi: pinctrl-12
= <&i2cmux_pins_i>;

> where driver_deferred_probe_check_state() is called before the supplier
> has probed successfully or before deferred probe timeout has expired.
>
> So, delete the call and replace it with -ENODEV.
>
> Signed-off-by: Saravana Kannan <saravanak@google.com>

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds
Saravana Kannan June 5, 2022, 3:41 a.m. UTC | #2
On Mon, May 30, 2022 at 2:22 AM Geert Uytterhoeven <geert@linux-m68k.org> wrote:
>
> Hi Saravana,
>
> Thanks for your patch!
>
> On Thu, May 26, 2022 at 10:16 AM Saravana Kannan <saravanak@google.com> wrote:
> > Now that fw_devlink=on by default and fw_devlink supports
> > "pinctrl-[0-8]" property, the execution will never get to the point
>
> 0-9?
>
> oh, it's really 0-8:
>
>     drivers/of/property.c:DEFINE_SIMPLE_PROP(pinctrl0, "pinctrl-0", NULL)
>     drivers/of/property.c:DEFINE_SIMPLE_PROP(pinctrl1, "pinctrl-1", NULL)
>     drivers/of/property.c:DEFINE_SIMPLE_PROP(pinctrl2, "pinctrl-2", NULL)
>     drivers/of/property.c:DEFINE_SIMPLE_PROP(pinctrl3, "pinctrl-3", NULL)
>     drivers/of/property.c:DEFINE_SIMPLE_PROP(pinctrl4, "pinctrl-4", NULL)
>     drivers/of/property.c:DEFINE_SIMPLE_PROP(pinctrl5, "pinctrl-5", NULL)
>     drivers/of/property.c:DEFINE_SIMPLE_PROP(pinctrl6, "pinctrl-6", NULL)
>     drivers/of/property.c:DEFINE_SIMPLE_PROP(pinctrl7, "pinctrl-7", NULL)
>     drivers/of/property.c:DEFINE_SIMPLE_PROP(pinctrl8, "pinctrl-8", NULL)
>
> Looks fragile, especially since we now have:
>
>     arch/arm64/boot/dts/microchip/sparx5_pcb134_board.dtsi:
> pinctrl-9 = <&i2cmux_9>;
>     arch/arm64/boot/dts/microchip/sparx5_pcb134_board.dtsi: pinctrl-10
> = <&i2cmux_10>;
>     arch/arm64/boot/dts/microchip/sparx5_pcb134_board.dtsi: pinctrl-11
> = <&i2cmux_11>;
>     arch/arm64/boot/dts/microchip/sparx5_pcb134_board.dtsi: pinctrl-12
> = <&i2cmux_pins_i>;

Checking for pinctrl-* and then verifying if * matches %d would be
more complicated and probably more expensive compared to listing
pinctrl-[0-8]. Especially because more than 50% of pinctrl-*
properties in DT files are NOT pinctrl-%d. So back when we merged
this, Rob and I agreed [0-8] was good enough for now and we can add
more if we needed to. Also, when I checked back then, all the
pinctrl-5+ properties ended up pointing to the same suppliers as the
lower numbered ones. So it didn't make a difference.

Ok, I just checked linux-next all the pinctrl-9+ instances and it's
still true that they all point to the same supplier pointed to by
pinctrl-[0-8].

So yeah, it looks fragile, but is not broken and it's more efficient
than looking for pinctrl-%d or adding more pinctrl-xx entries. So,
let's fix it if it actually breaks? Not going to oppose a patch if
anyone wants to make it more complete.


-Saravana

>
> > where driver_deferred_probe_check_state() is called before the supplier
> > has probed successfully or before deferred probe timeout has expired.
> >
> > So, delete the call and replace it with -ENODEV.
> >
> > Signed-off-by: Saravana Kannan <saravanak@google.com>
>
> Gr{oetje,eeting}s,
>
>                         Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
>
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
>                                 -- Linus Torvalds
Andy Shevchenko June 6, 2022, 10:17 a.m. UTC | #3
On Sat, Jun 04, 2022 at 08:41:01PM -0700, Saravana Kannan wrote:
> On Mon, May 30, 2022 at 2:22 AM Geert Uytterhoeven <geert@linux-m68k.org> wrote:
> > On Thu, May 26, 2022 at 10:16 AM Saravana Kannan <saravanak@google.com> wrote:
> > > Now that fw_devlink=on by default and fw_devlink supports
> > > "pinctrl-[0-8]" property, the execution will never get to the point
> >
> > 0-9?
> >
> > oh, it's really 0-8:
> >
> >     drivers/of/property.c:DEFINE_SIMPLE_PROP(pinctrl0, "pinctrl-0", NULL)
> >     drivers/of/property.c:DEFINE_SIMPLE_PROP(pinctrl1, "pinctrl-1", NULL)
> >     drivers/of/property.c:DEFINE_SIMPLE_PROP(pinctrl2, "pinctrl-2", NULL)
> >     drivers/of/property.c:DEFINE_SIMPLE_PROP(pinctrl3, "pinctrl-3", NULL)
> >     drivers/of/property.c:DEFINE_SIMPLE_PROP(pinctrl4, "pinctrl-4", NULL)
> >     drivers/of/property.c:DEFINE_SIMPLE_PROP(pinctrl5, "pinctrl-5", NULL)
> >     drivers/of/property.c:DEFINE_SIMPLE_PROP(pinctrl6, "pinctrl-6", NULL)
> >     drivers/of/property.c:DEFINE_SIMPLE_PROP(pinctrl7, "pinctrl-7", NULL)
> >     drivers/of/property.c:DEFINE_SIMPLE_PROP(pinctrl8, "pinctrl-8", NULL)
> >
> > Looks fragile, especially since we now have:
> >
> >     arch/arm64/boot/dts/microchip/sparx5_pcb134_board.dtsi:
> > pinctrl-9 = <&i2cmux_9>;
> >     arch/arm64/boot/dts/microchip/sparx5_pcb134_board.dtsi: pinctrl-10
> > = <&i2cmux_10>;
> >     arch/arm64/boot/dts/microchip/sparx5_pcb134_board.dtsi: pinctrl-11
> > = <&i2cmux_11>;
> >     arch/arm64/boot/dts/microchip/sparx5_pcb134_board.dtsi: pinctrl-12
> > = <&i2cmux_pins_i>;
> 
> Checking for pinctrl-* and then verifying if * matches %d would be
> more complicated and probably more expensive compared to listing
> pinctrl-[0-8]. Especially because more than 50% of pinctrl-*
> properties in DT files are NOT pinctrl-%d. So back when we merged
> this, Rob and I agreed [0-8] was good enough for now and we can add
> more if we needed to. Also, when I checked back then, all the
> pinctrl-5+ properties ended up pointing to the same suppliers as the
> lower numbered ones. So it didn't make a difference.
> 
> Ok, I just checked linux-next all the pinctrl-9+ instances and it's
> still true that they all point to the same supplier pointed to by
> pinctrl-[0-8].
> 
> So yeah, it looks fragile, 

And feels fragile, adds into confusion, etc.
Please, consider redesigning this to be more robust.

>	but is not broken and it's more efficient
> than looking for pinctrl-%d or adding more pinctrl-xx entries. So,
> let's fix it if it actually breaks? Not going to oppose a patch if
> anyone wants to make it more complete.
> 
> > > where driver_deferred_probe_check_state() is called before the supplier
> > > has probed successfully or before deferred probe timeout has expired.
> > >
> > > So, delete the call and replace it with -ENODEV.
diff mbox series

Patch

diff --git a/drivers/pinctrl/devicetree.c b/drivers/pinctrl/devicetree.c
index 3fb238714718..ef898ee8ca6b 100644
--- a/drivers/pinctrl/devicetree.c
+++ b/drivers/pinctrl/devicetree.c
@@ -129,7 +129,7 @@  static int dt_to_map_one_config(struct pinctrl *p,
 		np_pctldev = of_get_next_parent(np_pctldev);
 		if (!np_pctldev || of_node_is_root(np_pctldev)) {
 			of_node_put(np_pctldev);
-			ret = driver_deferred_probe_check_state(p->dev);
+			ret = -ENODEV;
 			/* keep deferring if modules are enabled */
 			if (IS_ENABLED(CONFIG_MODULES) && !allow_default && ret < 0)
 				ret = -EPROBE_DEFER;