Hi Heiner,
> It was reported that on a system with nfsboot and w/o initramfs network
> fails because trying to load the PHY driver returns -ENOENT. Reason was
> that due to missing initramfs the modprobe binary isn't available.
> So we have to ignore error code -ENOENT.
>
> Fixes: 13d0ab6750b2 ("net: phy: check return code when requesting PHY driver
> module")
> Reported-by: Krzysztof Kozlowski <k...@kernel.org>
> Signed-off-by: Heiner Kallweit <hkallwe...@gmail.com>
Thanks for your patch!
>
> --- a/drivers/net/phy/phy_device.c
> +++ b/drivers/net/phy/phy_device.c
> @@ -552,10 +552,12 @@ static int phy_request_driver_module(struct phy_device
> *dev, int phy_id)
>
> ret = request_module(MDIO_MODULE_PREFIX MDIO_ID_FMT,
> MDIO_ID_ARGS(phy_id));
> - /* we only check for failures in executing the usermode binary,
> - * not whether a PHY driver module exists for the PHY ID
> + /* We only check for failures in executing the usermode binary,
> + * not whether a PHY driver module exists for the PHY ID.
> + * Accept -ENOENT because this may occur in case no initramfs exists,
> + * then modprobe isn't available.
> */
> - if (IS_ENABLED(CONFIG_MODULES) && ret < 0) {
> + if (IS_ENABLED(CONFIG_MODULES) && ret < 0 && ret != -ENOENT) {
> phydev_err(dev, "error %d loading PHY driver module for ID
> 0x%08x\n",
> ret, phy_id);
> return ret;
While I believe this patch fixes the particular issue I was seeing, I'm
not convinced it fixes other possible issues. There are several
different error cases in both the kernel (e.g. -ETIME) and userland that
can cause request_module() to fail, without actually having any impact,
if the particular PHY driver is builtin or already loaded.
IMHO, if the wanted PHY is available, all errors returned by
request_module() should be ignored.
In other subsystems, this is handled like:
if (driver_is_missing)
request_module(...);
if (driver_is_missing)
return -E...;
Note that most callers of request_module() don't even check the error
code it returns: the only thing that matters is if the (possibly loaded)
functionality is available afterwards or not.
Thanks!
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- ge...@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
