On 21/03/2025 at 00:15, Geert Uytterhoeven wrote:
> 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.
>
> Fix this by re-instating the property presence check (this time using
> the proper API) in a wrapper around devm_mux_state_get(). When the
> multiplexer subsystem gains support for optional muxes, the wrapper can
> just be removed.
>
> In addition, propagate all real errors upstream, instead of ignoring
> them.
I would like to hear Rob's opinion on this. In d02dfd4ceb2e9f34 Rob
purposely changed the function to ignore errors other than EPROBE_DEFER.
Right now, I do not see a reason not to propagate the other errors, so
I am in favor of this roll back. But maybe we are missing something?
Otherwise, the patch looks good to me. Nice improvement over the v1. I
will wait for Rob's comment to give my review tag.
> Fixes: d02dfd4ceb2e9f34 ("phy: can-transceiver: Drop unnecessary "mux-states" property presence check")
> Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> ---
> Alternatively, the multiplexer subsystem needs to gain support for
> getting an optional mux...
>
> v2:
> - Add and use devm_mux_state_get_optional(),
> - No given tags added, as the new solution is different.
> ---
> drivers/phy/phy-can-transceiver.c | 22 +++++++++++++++-------
> 1 file changed, 15 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/phy/phy-can-transceiver.c b/drivers/phy/phy-can-transceiver.c
> index 2bec70615449f94d..f59caff4b3d4c267 100644
> --- a/drivers/phy/phy-can-transceiver.c
> +++ b/drivers/phy/phy-can-transceiver.c
> @@ -93,6 +93,16 @@ static const struct of_device_id can_transceiver_phy_ids[] = {
> };
> MODULE_DEVICE_TABLE(of, can_transceiver_phy_ids);
>
> +/* Temporary wrapper until the multiplexer subsystem supports optional muxes */
> +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);
> +}
> +
> static int can_transceiver_phy_probe(struct platform_device *pdev)
> {
> struct phy_provider *phy_provider;
> @@ -114,13 +124,11 @@ static int can_transceiver_phy_probe(struct platform_device *pdev)
> match = of_match_node(can_transceiver_phy_ids, pdev->dev.of_node);
> drvdata = match->data;
>
> - mux_state = devm_mux_state_get(dev, NULL);
> - if (IS_ERR(mux_state)) {
> - if (PTR_ERR(mux_state) == -EPROBE_DEFER)> - return PTR_ERR(mux_state);
> - } else {
> - can_transceiver_phy->mux_state = mux_state;
> - }
> + mux_state = devm_mux_state_get_optional(dev, NULL);
> + if (IS_ERR(mux_state))
> + return PTR_ERR(mux_state);
> +
> + can_transceiver_phy->mux_state = mux_state;
>
> phy = devm_phy_create(dev, dev->of_node,
> &can_transceiver_phy_ops);
Yours sincerely,
Vincent Mailhol
