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. 於 三，2009-11-25 於 18:26 -0500，Alan Stern 提到： > 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. Thank's Joey Lee -- 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
