Hi Vincent,

On Wed, 19 Mar 2025 at 15:07, Vincent Mailhol
[off-list ref] wrote:

For some reasons, I received your message twice (with a two minutes
interval between both messages). These look identical. I am answering

My scripting didn't handle the comment in Rob's address correctly,
so I resent the patch with the fixed address.

the most recent. :)

Good ;-)

On 19/03/2025 at 22:27, Geert Uytterhoeven wrote:

quoted

On the Renesas Gray Hawk Single development board:

    can-transceiver-phy can-phy0: /can-phy0: failed to get mux-state (0)

"mux-states" is an optional property for CAN transceivers.  However,
mux_get() always prints an error message in case of an error, including
when the property is not present, confusing the user.

Hmmm, I understand why you are doing this patch. But on the long term,
wouldn't it make more sense to have a devm_mux_state_get_optional()? Or
maybe add a property somewhere to inform devm_mux_state_get() that this
is optional?

Regardless, just see this as an open question. I am OK with the approach
of your patch.

Alternatively, we can be proactive and add a temporary local wrapper:

    /* Dummy wrapper until optional muxes are supported */
    static inline struct mux_state *
    devm_mux_state_get_optional(struct device *dev, const char *mux_name)
    {
            if (!of_property_present(dev->of_node, "mux-states"))
                    return NULL;

            return devm_mux_state_get(dev, mux_name);
    }

and call that instead?  Then the probe function needs no future changes
when the real devm_mux_state_get_optional() arrives.

quoted

Fix this by re-instating the property presence check.

This is bascially a revert of commit d02dfd4ceb2e9f34 ("phy:
can-transceiver: Drop unnecessary "mux-states" property presence
check"), with two changes:
  1. Use the proper API for checking whether a property is present,
  2. Do not print an error message, as the mux core already takes care
     of that.

Fixes: d02dfd4ceb2e9f34 ("phy: can-transceiver: Drop unnecessary "mux-states" property presence check")> Signed-off-by: Geert Uytterhoeven [off-list ref]

Notwithstanding of above comment:

Reviewed-by: Vincent Mailhol <redacted>

Thanks!

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

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