Messages in this thread | | | Date | Wed, 18 Jul 2018 23:50:33 -0700 | From | Tony Lindgren <> | Subject | Re: [PATCH v1 0/3] console, serial8250: Disable PM and DMA ops |
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* Andy Shevchenko <andriy.shevchenko@linux.intel.com> [180718 14:54]: > On Wed, 2018-05-23 at 11:00 -0700, Tony Lindgren wrote: > > I thought you said earlier the issue was that you wanted to keep > > the console enabled all the time and never idle? > > Yes, for kernel console. > To be clear, if user supplies "console=ttySx" it keeps powered on > always. But if there is no such parameter, we are fine with RPM.
I'm fine with that as long as we have a way to detach or disable kernel console from userspace after booting so the console uart can idle.
> Letting kernel console do power management on the systems without > irq_safe hack is dangerous in terms of loosing important data (crash, or > some other stuff which needs atomic context: kgdb?).
Yes in the long run we should get rid of all pm_runtime_irq_safe() use. It increases the parent dev PM runtime usage count permanently blocking the whole domain from idling.
Regards,
Tony
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