Re: [ACPI] s4bios: does anyone use it?

[Stefan Seyfried <seife@suse.de>]

Pavel Machek wrote:
> Hi!
> 
>> >Okay, so we had 2 users in past but have 0 users now? :-).
>> I wonder how could anyone use S4BIOS in 2.6.11. S4 and S4b all came into
>> 'enter_state'. and in acpi_sleep_init:
>> 
>> 		if (i == ACPI_STATE_S4) {
>> 			if (acpi_gbl_FACS->S4bios_f) {
>> 				sleep_states[i] = 1;
>> 				printk(" S4bios");
>> 				acpi_pm_ops.pm_disk_mode =
>> PM_DISK_FIRMWARE;
>> 			}
>> 			if (sleep_states[i])
>> 				acpi_pm_ops.pm_disk_mode =
>> PM_DISK_PLATFORM;
>> 		}
>> That means we actually can't set PM_DISK_FIRMWARE (always set
>> PM_DISK_PLATFORM). Is this intended? If no, .pm_disk_mode should be a
>> mask.
> 
> pm_disk_mode is settable using /sys/power/disk, no?

No, it isn't. That was my original point: you can write "firmware" into
it, but it has no effect. This probably was a side-effect of the "make
firmware mode not default" patch from a year ago.
But the real question is: what is firmware mode good for today? Is there
a single machine where firmware mode once worked, but swsusp does not
work today?

> Anyway, what about this, then?
> 
> --- clean/Documentation/feature-removal-schedule.txt	2005-01-22 21:24:50.000000000 +0100
> +++ linux/Documentation/feature-removal-schedule.txt	2005-03-08 10:18:05.000000000 +0100

Fine with me. I think it cannot work since ~one year (when we changed
the default from "firmware if available" to "shutdown always", the code
piece cited above) and nobody complained until now, so it won't be
missed IMO.
-- 
Stefan Seyfried, QA / R&D Team Mobile Devices, SUSE LINUX Nürnberg.

"Any ideas, John?"
"Well, surrounding them's out."