[ltp] no C3 state in X - but i do get to C3 with X running but not displayed on screen

Thomas Breitner linux-thinkpad@linux-thinkpad.org
Wed, 06 Apr 2005 18:22:12 +0200


Hi,

> Hi Brad.
> 
> 
> On Mi, 2005-04-06 at 11:12 -0400, Brad Langhorst wrote:
> > when i'm at vt1 my computer spends time in C3 state
> > but when i'm in X C3 never gets entered...  I don't have to stop X to
> > enter C3 - i just have to switch to another virtual terminal.
> 
> Interesting. Does not me help here.

my situation with C3 on a t42p is like this:

a) C3 impossible:
usb-modules:
mala:/home/theo# lsmod | grep usb
usbhid                 32064  0
usbcore               106808  4 ehci_hcd,usbhid,uhci_hcd
+
usb2.0-hub detached to usb-port on t42p

b) C3 impossible:
usb-modules like under a)
+
usb2.0-hub detached to usb-port with an additional usb1.1-mouse

c) C3 impossible:
usb-modules like under a) and b)
+
usb1.1-mouse

d) C3 possible:
usb-modules like under a), b) and c)
+
NO devices attached to usb-port


No matter if on X or on a vt, doesnt't even matter if uhci_hcd is
loaded. So, it seems that in my case it's not the uhci_hcd-module which
is causing to block C3, but some *activity* which is handled by
uhci_hcd.

debian kernel 2.6.11 (custom)

Greetings,
thomas

> 
> > I have ehci_hcd and uhci_hcd loaded (but no devices attached).
> 
> I have to unload uhci_hcd to enable C3 (the bus master activity is only
> caused by this module here).
> 
> Nothing else, even ehci_hcd can stay active (which puts me into the
> interesting position that I can use an USB2 drive, but not an USB1 mouse
> if I want C3, for example. ts.. ;))
> 
> 
> Greetings, UW(e)
> 
> 
> 
-- 
_____________________________________________
Thomas Breitner

mail@tombreit.de   |   http://www.tombreit.de