On 16.07.2008 19:35, Segher Boessenkool wrote: >> When the field is implemented the question >> is what should it be. > > Yes. > >> The wording is pretty clear elsewhere that the subsystem vendor id >> should equal your normal pci vendor id of the manufacturer. > > The ID of the manufacturer of the subsystem, yes; or zero.
Agreed. For my laptop, the Intel Pro/Wireless 2200BG is the one onboard(?) device which has a different subsystem vendor ID from all the others. That probably means it is on a different PCB. >> The subsystem device id is the ambiguous one. > > Indeed. Yes. I have seen both: - one common subsystem device ID for all onboard devices (my laptop board) - completely different subsystem device IDs for each onboard device (my desktop board) >> It seems clear from that proposal that subsys vendor id subsys device id >> is not unique enough to identify a driver in general. > > Unfortunate, but true. > >> I just figure the default should be the current behavior. > > Remind me, what _is_ the current behaviour? > > I see two options: > > a) Don't program it, leave it at 0. > b) Program it the same as the factory BIOS does. > > There is a bunch of problems with b): > > -- We have to keep a list of mainboards, and the user has to configure > for that mainboard, even if that board is essentially identical to > a whole host of other boards; We already do that. v2 and v3 targets are per-mainboard because SuperI/O settings have to be tweaked individually anyway, sometimes even per board revision due to different fan cabling etc. > -- Every chip is programmed differently, so we need a driver for every > chip, even if coreboot doesn't care about any other chip specifics; Hm. I don't understand that. Why can't a generic PCI device handle the setting of the subsystem IDs? > -- OS drivers using this subsystem ID might use it to decide the chip > is configured in a certain way. We need to be bug-for-bug compatible in most cases anyway. > What are the downsides to not programming an SSID/SSVID? Except non-matching drivers and non-matching flashrom entries? I think some vendor tools use subsystem IDs as a way to verify they are running on hardware of a specific vendor. Regards, Carl-Daniel -- http://www.hailfinger.org/ -- coreboot mailing list [email protected] http://www.coreboot.org/mailman/listinfo/coreboot
