Re: [PATCH] 2.5.14 IDE 56

benh@kernel.crashing.org
Tue, 7 May 2002 19:19:46 +0200


> /driverfs/root/pci0/00:1f.4/usb_bus/000/
>
>and it wouldn't be impossible (or even necessarily very hard) to make an
>IDE controller export the "IDE device tree" the same way a USB controller
>now exports the "USB device tree".
>
>For things like hotplug etc, I think driverfs is eventually the only way
>to go, simply because it gives you the full (and unambiguous) path to
>_any_ device, and is completely bus-agnostic.
>
>But there is definitely a potential backwards-compatibility-issue.

One interesting thing here would be to have some optional link between
the bus-oriented device tree and the function-oriented tree (ie. devfs
or simply /dev). For example, an IDE node in driverfs could eventually
hold symlinks to the entries it provides in /dev when using devfs (or
just provide major/minor when not using devfs).

What do you think ?

One problem I've been faced with on ppc is to be able to match
a linux device with what the firmware (Open Firmware) thinks that
device is. The firmware view is bus-centered and it would be pretty
easy to provide some additional entries in driverfs that give the
OF fullpath of a given device. But then, the link between the actual
driver in driverfs and the "device" as used by, for example, the
filesystem isn't trivial.

Ben.

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/