On Monday 16 May 2005 12:02 pm, Fabrice Gautier wrote: > > > > There's PCI ... and PCI with PM capabilities. That rule about only > > issuing PME transactions while suspended can only apply in the latter > > case. That is, not all PCI devices support the PCI PM rules; drivers > > may need to help the hardware. > > You mean, you support some kind of power management on PCI devices without > PM capabilities ? How are you even sure that the pci_set_power_state will > work in those kind of devices. Linux must certainly support suspend() and resume() methods for such devices. In terms of PCI PM terminology, they will either stay in the PCI_D0 state during suspend, or go into PCI_D3cold ... and in the latter case, the device driver's resume() is going to have to know how to reinit from a reset state. (They already have code to init from that state, so it should be no problem.) By definition, pci_set_power_state() will be a NOP. There might be firmware that knows how to switch power on/off, or maybe not; that would be board-specific. > In any case, anyway it works I would say this is very much device specific > and not really part of a reference implementation. This is supposed to be a > reference implementation for "PCI PM compliant" devices right ? It was supposed to be a reference implementation, yes. But if it was only for one subset of PCI devices, I didn't notice any suggestion of that before now. The "works for small subset" implementation wouldn't be anywhere near as useful. - Dave
