On Saturday, June 08, 2013 09:17:13 AM Yanmin Zhang wrote: > On Sat, 2013-06-08 at 02:54 +0200, Rafael J. Wysocki wrote: > > On Saturday, June 08, 2013 08:42:12 AM Yanmin Zhang wrote: > > > On Fri, 2013-06-07 at 12:36 +0200, Rafael J. Wysocki wrote: > > > > On Friday, June 07, 2013 04:20:30 PM shuox....@intel.com wrote: > > > > > dpm_run_callback is used in other stages of power states changing. > > > > > It provides debug info message and time measurement when call these > > > > > callback. We also want to benefit ->prepare and ->complete. > > > > > > > > > > [PATCH 1/2] PM: use dpm_run_callback in device_prepare > > > > > [PATCH 2/2] PM: add dpm_run_callback_void and use it in > > > > > device_complete > > > > > > > > Is this an "Oh, why don't we do that?" series, or is it useful for > > > > anything > > > > in practice? I'm asking, because we haven't added that stuff to start > > > > with > > > > since we didn't see why it would be useful to anyone. > > > > > > > > And while patch [1/2] reduces the code size (by 1 line), so I can see > > > > some > > > > (tiny) benefit from applying it, patch [2/2] adds more code and is > > > > there any > > > > paractical reason? > > > Sometimes, suspend-to-ram path spends too much time (either suspend slowly > > > or wakeup slowly) and we need optimize it. > > > With the 2 patches, we could collect initcall_debug printk info and > > > manually > > > check what prepare/complete callbacks consume too much time. > > > > Well, can you point me to a single driver where prepare/complete causes this > > type of problems to happen? > > That's a good question. We are enabling Android mobiles and need optimize > suspend-to-ram. In the current upstream, we don't find a driver's > prepare/complete > callback spends too much time.
I understand your needs, but I don't think prepare/complete are likely to take too much time on Android either. Thanks, Rafael -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- 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/
