Messages in this thread | | | Subject | Re: [PATCH 3/6] PCI legacy I/O port free driver (take2) - Add device_flags into pci_device_id | From | Benjamin Herrenschmidt <> | Date | Thu, 23 Feb 2006 13:37:38 +1100 |
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On Tue, 2006-02-21 at 13:10 -0800, Greg KH wrote: > On Tue, Feb 21, 2006 at 09:59:51PM +0100, Andi Kleen wrote: > > On Tuesday 21 February 2006 21:56, Greg KH wrote: > > > > > I don't think you can add fields here, after the driver_data field. It > > > might mess up userspace tools a lot, as you are changing a userspace > > > api. > > > > User space should look at the ASCII files (modules.*), not the binary > > As long as the code to generate these files still works it should be ok. > > Does it? Shouldn't the tools export this information too, if it really > should belong in the pci_id structure? > > So, is _every_ pci driver going to have to be modified to support this > new field if they are supposed to work on this kind of hardware? If so, > that doesn't sound like a good idea. Any way we can just set the bit in > the pci arch specific code for the devices instead?
I think the right approach is to not change driver_data but instead to add a new version of pci_enable_device() (I call it pci_enable_resources() but you are welcome to find something more fancy) to enable a selected set of resources with the old pci_enable_device() just calling the new one with a full mask set.
I don't like the driver_data approach. I don't like the static table approach in fact. Drivers may "know" wether they need to enable/disable given resources based on other things like revision, etc... Some drivers may want to enable only one BAR, access some registers to properly figure out what rev of a device they are talking to, then selectively enable other BARs and/or MSIs etc...
I think the driver should be in control... flags in a static table aren't flexible enough.
Ben.
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