Messages in this thread | | | Date | Mon, 8 Nov 2004 20:58:43 -0800 | From | Greg KH <> | Subject | Re: [PATCH/RFC 1/4]device core changes |
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On Tue, Nov 09, 2004 at 11:35:41AM +0800, Li Shaohua wrote: > On Tue, 2004-11-09 at 08:50, Li Shaohua wrote: > > On Tue, 2004-11-09 at 06:58, Greg KH wrote: > > > On Mon, Nov 08, 2004 at 12:11:11PM +0800, Li Shaohua wrote: > > > > Hi, > > > > This is the device core change required. Add .platform_bind method for > > > > bus_type, so platform can do addition things when add a new device. A > > > > case is ACPI, we want to utilize some ACPI methods for physical devices. > > > > 1. Why doesn't use 'platform_notify'? > > > > Current device core has a 'platform_notify' mechanism, but it's not > > > > sufficient for this. Only sepcific bus type know how to parse dev.bus_id > > > > and know how to encode specific device's address into ACPI _ADR syntax. > > > > > > I don't see why platform_notify is not sufficient. This is the exact > > > reason it was added to the code. > > As I said in the email, we need know the bus type to decode and encode > > address. If you use platform_notify, you must do something like this: > > switch (dev->bus) > > { > > case pci_bus_type: > > bind PCI devices with ACPI devices > > break; > > case ide_bus_type: > > bind IDE devices with ACPI devices > > break; > > .... > > } > > But note this method requires all bus types are build-in. If a bus type > > is in a loadable module (such as IDE bus), the method will failed. I > > searched current tree, only ARM implemented 'platform_notify', but ARM > > only cares PCI bus, ACPI cares about all bus types. > > > > Oops, it's my bad. we can identify the bus type from bus_type->name, but > it looks like a little ugly. Why the bus_type hasn't a flag to identify > which bus it is?
Because if you have a struct bus * you _have_ to know what type it is.
> Anyway, thanks Greg. I will add as you said.
Hm, hopefully Pat will chime in about what would be best for this, as he created the platform_notify interface.
thanks,
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