Re: [linux-usb-devel] Re: [BK PATCH] USB update for 2.6.3

Benjamin Herrenschmidt
2004-02-20T07:52:41Z

> If you mean the USB target device itself, can't you walk the
> tree until you find a device that is no longer on bus_type
> usb to determine your root?

I don't feel like walking the tree on each pci_dma access

> You could stuff that into platform_data on PCI devices on your platforms.

I want automatic inheritance to child devices, shouldb't be _that_
difficult to do ;)

> I think we're not quite there yet, but once you have the device
> struct, in theory, you can walk up the tree to grab the platform_data
> for say the device's parent and do any tweaks based on platform-specific
> bus parameters. With PCI, you could even stuff this into pci_bus->sysdata.
>
> I think having a function pointer table for things like dma mapping
> and ioremap on all devices would be a very good thing, but not sure
> if the powers that be would allow that in 2.6.
>
> ~Deepak
--
Benjamin Herrenschmidt <benh@kernel.crashing.org>