On Fri, 2011-08-05 at 09:57 +0800, Liu, ShuoX wrote: > > On Thursday, August 04, 2011, Greg KH wrote: > > > On Thu, Aug 04, 2011 at 01:13:38PM +0800, Liu, ShuoX wrote: > > > > >From a906b0b5b4ff3414ceb9fc7a69a3d7c9d66e46b1 Mon Sep 17 > > 00:00:00 2001 > > > > From: ShuoX Liu <shuox.liu@xxxxxxxxx> > > > > Date: Thu, 28 Jul 2011 10:54:22 +0800 > > > > Subject: [PATCH] PM: add statistics sysfs file for suspend to ram. > > > > > > What's this stuff here for? That's not needed (hint, I would have to > > > edit it out by hand to be able to apply this patch.) > > > > > > Thanks for resending a version that passes checkpatch.pl and could be > > > applied, but all of my previous comments still stand. This patch, as > > > is, is totally unacceptable. > > > > Agreed, plus I'd like to know the motivation behind it. That is, we have > > quite a few debug facilities in that code, so why are they insufficient? Thanks Greg, Rafael. We are changing the patch based on your comments. > > Some explanation from Yanmin, > "We are enabling power features on Medfield. Some testers and developers > complain they don't know if system tries suspend-2-ram, and what device > fails to suspend. They need such info for a quick check. If turning on > CONFIG_PM_DEBUG, we get too much info and testers need recompile > the system. Comparing with PC/notebook, a mobile enters/exits suspend-2-ram (we call it s3 on Medfield) far more frequently. If it can't enter suspend-2-ram in time, the power might be used up soon. We often find sometimes, a device suspend fails. Then, system retries s3 over and over again. As display is off, testers/developers don't know what happens. Teh system With the patch, we could know what the bad device is. The patch doesn't hurt performance as it's just statistics collector. CONFIG_PM_DEBUG is very useful for finer investigation about what happens behind. What we provide by the patch is to analyze the issues quickly, even by an ordinary tester. > > The patch records the suspend-2-ram fail/success statistics and the last 2 > failed devices. Users could find what device causes the failure quickly." We are modifying the patch. 1) move the sysfs entry to debugfs; 3) Add an explanation in file Documentation/power/basic-pm-debugging.txt. 2) Add more explanation, especially about the motivation, and how to use it, into the patch comments. Thanks again. Yanmin _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
