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74d9555580
Theoretically, when the hardware signature in FACS changes, the OS is supposed to gracefully decline to attempt to resume from S4: "If the signature has changed, OSPM will not restore the system context and can boot from scratch" In practice, Windows doesn't do this and many laptop vendors do allow the signature to change especially when docking/undocking, so it would be a bad idea to simply comply with the specification by default in the general case. However, there are use cases where we do want the compliant behaviour and we know it's safe. Specifically, when resuming virtual machines where we know the hypervisor has changed sufficiently that resume will fail. We really want to be able to *tell* the guest kernel not to try, so it boots cleanly and doesn't just crash. This patch provides a way to opt in to the spec-compliant behaviour on the command line. A follow-up patch may do this automatically for certain "known good" machines based on a DMI match, or perhaps just for all hypervisor guests since there's no good reason a hypervisor would change the hardware_signature that it exposes to guests *unless* it wants them to obey the ACPI specification. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> |
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| .. | ||
| autosleep.c | ||
| console.c | ||
| energy_model.c | ||
| hibernate.c | ||
| Kconfig | ||
| main.c | ||
| Makefile | ||
| power.h | ||
| poweroff.c | ||
| process.c | ||
| qos.c | ||
| snapshot.c | ||
| suspend.c | ||
| suspend_test.c | ||
| swap.c | ||
| user.c | ||
| wakelock.c | ||