On Wed, 25 Nov 2009, Joey Lee wrote: > Hi Alan, > > How are you! I am Joey and I have testing this issue. > We use a Aglient power metter for direct detect the Watt value to > battery. > > æ?¼ ä¸?ï¼?2009-11-25 æ?¼ 18:26 -0500ï¼?Alan Stern æ??å?°ï¼? > > On Wed, 25 Nov 2009, Greg KH wrote: > > > > > But, again, in testing, this didn't seem to actually make any > > > difference. Well, it did for about 50% of the time the machine was > > > tested, but not the other 50%. The other 50% always worked when echoing > > > "auto" to the power/level file. > > > > Did you look at the contents of the power/level file before writing > > "auto" to it? > > > > Yes, actually, GregKH's patch set the "auto" value to level sysfs by > default. > And I have check the level file before I echo "auto", the value is > "auto". > > Even the level value is "auto" then I echo "auto" to level sysfs again, > we found the Watt value on power metter can reserve (down) 0.6 Watt, > then never up back. > > > > > This doesn't make sense; it should have worked just as you thought. > > > > Have you tried adding printk statements to uvcvideo's suspend and > > resume routines, so you can see when the actual power transitions take > > place? > > > > Please kindly told me how to enable the printk in uvcvideo driver, I saw > those code but didn't get any log in messages file for uvcvideo. You have to do: rmmod uvcvideo modprobe uvcvideo trace=0x100 If you run from a VT console instead of an X window, and you do echo 8 >/proc/sys/kernel/printk before the modprobe, then the debug messages will show up on the screen as well as in the dmesg log. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
