On Mon, 2011-11-28 at 16:33 +0530, Deepthi Dharwar wrote: > On an LPAR if cpuidle is disabled, ppc_md.power_save is still set to > cpuidle_idle_call by default here. This would result in calling of > cpuidle_idle_call repeatedly, only for the call to return -ENODEV. The > default idle is never executed. > This would be a major design flaw. No fallback idle routine. > > We propose to fix this by checking the return value of > ppc_md.power_save() call from void to int. > Right now return value is void, but if we change this to int, this > would solve two problems. One being removing the cast to a function > pointer in the prev patch and this design flaw stated above. > > So by checking the return value of ppc_md.power_save(), we can invoke > the default idle on failure. But my only concern is about the effects of > changing the ppc_md.power_save() to return int on other powerpc > architectures. Would it be a good idea to change the return type to int > which would help us flag an error and fallback to default idle? I would have preferred an approach where the cpuidle module sets ppc_md.power_save when loaded and restores it when unloaded ... but that would have to go into the cpuidle core as a powerpc specific tweak and might not be generally well received. So go for it, add the return value, but you'll have to update all the idle functions (grep for power_save in arch/powerpc to find them). Cheers, Ben. _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/linux-pm
