Re: [PATCH v2 3/9] net: mdio: Delete usage of driver_deferred_probe_check_state()

Geert Uytterhoeven
2022-07-05T09:18:39Z

Hi Saravana,

On Wed, Jun 1, 2022 at 2:44 PM Saravana Kannan <saravanak@google.com> wrote:
> Now that fw_devlink=on by default and fw_devlink supports interrupt
> properties, 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>

Thanks for your patch, which is now commit f8217275b57aa48d ("net:
mdio: Delete usage of driver_deferred_probe_check_state()") in
driver-core/driver-core-next.

Seems like I missed something when providing my T-b for this series,
sorry for that.

arch/arm/boot/dts/r8a7791-koelsch.dts has:

&ether {
pinctrl-0 = <&ether_pins>, <&phy1_pins>;
pinctrl-names = "default";

phy-handle = <&phy1>;
renesas,ether-link-active-low;
status = "okay";

phy1: ethernet-phy@1 {
compatible = "ethernet-phy-id0022.1537",
"ethernet-phy-ieee802.3-c22";
reg = <1>;
interrupt-parent = <&irqc0>;
interrupts = <0 IRQ_TYPE_LEVEL_LOW>;
micrel,led-mode = <1>;
reset-gpios = <&gpio5 22 GPIO_ACTIVE_LOW>;
};
};

Despite the interrupts property, &ether is now probed before irqc0
(interrupt-controller@e61c0000 in arch/arm/boot/dts/r8a7791.dtsi),
causing the PHY not finding its interrupt, and resorting to polling:

-Micrel KSZ8041RNLI ee700000.ethernet-ffffffff:01: attached PHY
driver (mii_bus:phy_addr=ee700000.ethernet-ffffffff:01, irq=185)
+Micrel KSZ8041RNLI ee700000.ethernet-ffffffff:01: attached PHY
driver (mii_bus:phy_addr=ee700000.ethernet-ffffffff:01, irq=POLL)

Reverting this commit, and commit 9cbffc7a59561be9 ("driver core:
Delete driver_deferred_probe_check_state()") fixes that.

> --- a/drivers/net/mdio/fwnode_mdio.c
> +++ b/drivers/net/mdio/fwnode_mdio.c
> @@ -47,9 +47,7 @@ int fwnode_mdiobus_phy_device_register(struct mii_bus *mdio,
> * just fall back to poll mode
> */
> if (rc == -EPROBE_DEFER)
> - rc = driver_deferred_probe_check_state(&phy->mdio.dev);
> - if (rc == -EPROBE_DEFER)
> - return rc;
> + rc = -ENODEV;
>
> if (rc > 0) {
> phy->irq = rc;

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