Rafael J. Wysocki wrote: > From: Rafael J. Wysocki <rjw@xxxxxxx> > Subject: ACPI suspend: Blacklist boxes that require us to set SCI_EN directly on resume > > Some Apple boxes evidently require us to set SCI_EN on resume > directly, because if we don't do that, they hung somewhere in the > resume code path. Moreover, on these boxes it is not sufficient to > use acpi_enable() to turn ACPI on during resume. All of this is > against the ACPI specification which states that (1) the BIOS is > supposed to return from the S3 sleep state with ACPI enabled > (SCI_EN set) and (2) the SCI_EN bit is owned by the hardware and we > are not supposed to change it. > > For this reason, blacklist the affected systems so that the SCI_EN > bit is set during resume on them. > > [NOTE: Unconditional setting SCI_EN for all system on resume doesn't > work, because it makes some other systems crash (that's to be > expected). Also, it is not entirely clear right now if all of the > Apple boxes require this workaround.] This is rather gross. The usual question arises, why does Windows work without such a hack? Maybe there is no better solution for now, but somebody should really look into why the behavior is different in Linux.. _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
