On 09/28/2016 02:08 AM, Greg KH wrote:

On Tue, Sep 27, 2016 at 06:08:31PM -0400, Charles (Chas) Williams wrote:

quoted

From: Prarit Bhargava <redacted>

commit a59b679ab85635737947310323f2f2bcfa0664a7 upstream.

ACPICA commit 7bb77313091e52a846df4c9c2bea90be31bfb9d8

Eliminate warnings for "not found" _Sx errors, since these
are optional. Original NOT_FOUND status is still returned.

Original changes by Prarit Bhargava.
ACPICA BZ 1208.

Link: https://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_acpica_acpica_commit_7bb77313&d=DQIBAg&c=IL_XqQWOjubgfqINi2jTzg&r=fW5qRnAJyT1k33A0K2qxJUiM_Fvn25jBh6w5nZa0Av0&m=YKKMBH_Gf4p-1il4ccw3hyLri8yTMU5XVCo5WYuyFME&s=rSUXu0SVaMeo25EuS8kOBW7LahXj-pQY2NX989d_tsk&e=
Link: https://urldefense.proofpoint.com/v2/url?u=https-3A__bugs.acpica.org_show-5Fbug.cgi-3Fid-3D1208&d=DQIBAg&c=IL_XqQWOjubgfqINi2jTzg&r=fW5qRnAJyT1k33A0K2qxJUiM_Fvn25jBh6w5nZa0Av0&m=YKKMBH_Gf4p-1il4ccw3hyLri8yTMU5XVCo5WYuyFME&s=BNSdDtJiVLNjvXdV2y5FAkfZOODSN4lu0y507fBOY0c&e=
Signed-off-by: Prarit Bhargava <redacted>
Signed-off-by: Bob Moore <redacted>
Signed-off-by: Lv Zheng <redacted>
Signed-off-by: Rafael J. Wysocki <redacted>
Signed-off-by: Chas Williams <redacted>
---
 drivers/acpi/acpica/hwxface.c | 24 +++++++++++++++++-------
 1 file changed, 17 insertions(+), 7 deletions(-)

Why is this a patch needed for 4.4-stable?  What is it solving?  It
looks like it just maybe reduces some warning messages in the kernel
log?

Yes, that's exactly the reason.  End users get very nervous about
anything with big capitals letters that says NOT FOUND.  Yes, you
and I know they are harmless warnings but others perhaps haven't
dug far enough into ACPI to know this.  This is an attempt to
mitigate support callbacks for a non-issue.

Do a quick google seach for AE_NOT_FOUND Sleep State and you will
see endless posts about this "issue":

https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1485223
https://bbs.archlinux.org/viewtopic.php?id=189256
https://access.redhat.com/solutions/2478221

I need an ack from the ACPI maintainers before I can take such a
thing...

thanks,

greg k-h