On Tue, Apr 30, 2013 at 08:36:21PM -0700, Colin Cross wrote: > On Tue, Apr 30, 2013 at 4:30 PM, Greg Kroah-Hartman > <gre...@linuxfoundation.org> wrote: > > On Tue, Apr 30, 2013 at 03:28:33PM -0700, Zoran Markovic wrote: > >> From: Benoit Goby <ben...@android.com> > >> > >> Below is a patch from android kernel that detects a driver suspend > >> lockup and captures dump in the kernel log. Please review and provide > >> comments. > > > > There's this really cool thing called a watchdog driver that does stuff > > like this :) > > If the watchdog driver worked in this case this patch wouldn't exist.
Great, let's fix the watchdog timer then :) What's wrong with it? > >> Rather than hard-lock the kernel, dump the suspend thread stack and > >> BUG() when a driver takes too long to suspend. The timeout is set to > >> 12 seconds to be longer than the usbhid 10 second timeout. > >> > >> Exclude from the watchdog the time spent waiting for children that > >> are resumed asynchronously and time every device, whether or not they > >> resumed synchronously. > > > > No, don't add a driver-core-only timer, use the existing watchdog timers > > if you are worried about the kernel locking up. > > The watchdog timers are useless here. For one, they generally stop > when their driver suspend op is called, so you may not even have one > running when you lock up. But you can fix that, right? > More importantly, the purpose of this patch is to tell you which > driver locked up and hopefully why, and the watchdog driver will > usually result in a silent reset. I thought it was an option as to what the watchdog does when it triggers. > This patch will cause a stack trace of the driver suspend op that is > blocking suspend progress, even if that call does not happen in the > suspend thread. But who can see this, the machine is now dead. greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
