On Tue, Jul 14, 2020 at 04:22:12PM +0200, Marek Behún wrote:
> This adds config option CONFIG_MDIO_BUS_DEBUGFS which, when enabled,
> adds support to communicate with the devices connected to the MDIO
> via debugfs.
>
> For every MDIO bus this creates directory
> /sys/kernel/debug/mdio_bus/MDIO_BUS_NAME
> with files "addr", "reg" and "val".
> User can write device address to the "addr" file and register number to
> the "reg" file, and then can read the value of the register from the
> "val" file, or can write new value by writing to the "val" file.
>
> This is useful when debugging various PHYs or switches.
Hi Marek
Please work with Tobias Waldekranz <tob...@waldekranz.com>.
I'm not particularly keen on allowing write access to such registers,
but it seems like there is demand. But we don't want two ways to do
this.
> static int mdiobus_register_gpiod(struct mdio_device *mdiodev)
> {
> @@ -576,6 +577,12 @@ int __mdiobus_register(struct mii_bus *bus, struct
> module *owner)
> }
> }
>
> + err = mdiobus_register_debugfs(bus);
> + if (err) {
> + dev_err(&bus->dev, "mii_bus %s couldn't create debugfs
> entries\n", bus->id);
> + goto error;
> + }
FYI: You should never error out for debugfs. You should not even check
the return values from debugfs calls.
Andrew
