Hi, On Thu, Oct 24, 2024 at 03:48:26PM +0200, David Woodhouse wrote: > On 24 October 2024 14:54:41 CEST, Miguel Luis <miguel.luis@xxxxxxxxxx> wrote: > >Perhaps spec. F.b. could be accommodated by first invoking SYSTEM_OFF2 with > >PSCI_1_3_OFF_TYPE_HIBERNATE_OFF and checking its return value in case of a > >fallback to an invocation with 0x0 ? This already complies with F.b. The PSCI implementation is required to accept either 0 or 1 for HIBERNATE_OFF. Using 0 seems like a good choice for compatibility since ... > I wasn't aware there was any point. Are there any hypervisors which actually implemented it that way? Amazon Linux and Ubuntu guests already just use zero. > > We could add it later if such a hypervisor (now in violation of F.b) turns up, I suppose? IIUC, you're really wanting to 0x0 because there are hypervisors out there that violate the final spec and *only* accept this value. That's perfectly fine, but it'd help avoid confusion if the supporting comment was a bit more direct: /* * If no hibernate type is specified SYSTEM_OFF2 defaults to * selecting HIBERNATE_OFF. * * There are hypervisors in the wild that violate the spec and * reject calls that explicitly provide a hibernate type. For * compatibility with these nonstandard implementations, pass 0 * as the type. */ if (system_entering_hibernation()) invoke_psci_fn(PSCI_FN_NATIVE(1_3, SYSTEM_OFF2), 0 , 0, 0); Thoughts? -- Thanks, Oliver
