http://bugzilla.kernel.org/show_bug.cgi?id=13145





--- Comment #13 from Anonymous Emailer <anonym...@kernel-bugs.osdl.org>  
2009-04-22 22:54:32 ---
Reply-To: l...@kernel.org

This is not a re-gression, it is a pro-gression:-)

In the CONFIG_CPU_IDLE=y case, there was a bug where we
would enter C3 even in the presence of bus master activity.
That bug was fixed by commit fc2e4009300088813c3be2de80b01ddc2399999e
"cpuidle: update the last_state acpi cpuidle reflecting actual state entered"

which shipped in 2.6.27

I've reproduced this issue on my t41, and when i revert the the
patch above from 2.6.27, we erroneously attempt to enter C3
in the face of bus master activity, just like we did in 2.6.25 and 2.6.26.

Note that the CONFIG_CPU_IDLE=n case never had this bug,
so you'd not see C3 with USB in that case even in older kernels.

Note also that /proc/acpi/processor/CPU/power does not
display any bus master activity for the CONFIG_CPU_IDLE=y
case, even when such activity is present.  Now that
CONFIG_CPU_IDLE=y for ACPI always, I think we should
simply delete that misleading field.

thanks,
Len Brown, Intel Open Source Technology Center

-- 
Configure bugmail: http://bugzilla.kernel.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are on the CC list for the bug.

------------------------------------------------------------------------------
Stay on top of everything new and different, both inside and 
around Java (TM) technology - register by April 22, and save
$200 on the JavaOne (SM) conference, June 2-5, 2009, San Francisco.
300 plus technical and hands-on sessions. Register today. 
Use priority code J9JMT32. http://p.sf.net/sfu/p
_______________________________________________
acpi-bugzilla mailing list
acpi-bugzilla@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/acpi-bugzilla

Reply via email to