Messages in this thread | | | Date | Thu, 20 Feb 2014 10:37:31 +0000 | From | Lorenzo Pieralisi <> | Subject | Re: [PATCH RFC v1 3/3] ARM hibernation / suspend-to-disk |
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On Wed, Feb 19, 2014 at 07:10:31PM +0000, Russ Dill wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > On 02/19/2014 08:12 AM, Lorenzo Pieralisi wrote: > > + * https://patchwork.kernel.org/patch/96442/ >
I am guessing the snippets of code your comments refer to.
> I think the idea here is to get the CPU into a state so that later > when we resume from the resume kernel, the actual CPU state matches > the state we have in kernel. The main thing flush_thread does is clear > out any and all FP state.
Which has already been saved through syscore_suspend()....
> The may be part of the patchset that is OBE.
It has to be updated then.
> cpu_resume makes many assumptions about the state of the state of the > CPU, the primary being that the MMU is disabled, but also that all > caches and IRQs are disabled. soft_restart does all this for us. > > > > ah, you are saying just return from __swsusp_arch_save_image and allow > cpu_suspend_abort to be called, placing the result of swsusp_save > somewhere else. This may work and would reduce the complexity of the > code slightly.
Yes. Basically you are doing a soft reboot just to return 0.
> This is taken from the previous iteration of the patchset, I think the > comment is OBE.
Updated it please then.
> But this is still required to select the right mapping for our copying.
/me confused. Please describe what switching to idmap is meant to achieve. In the patch above the copied swapper pgdir is not even used, I would like to understand why this is done.
> I don't remember why I needed to prevent gcc from manipulating the > stack here.
That's not a good reason to mark a function with attr __naked. If it is needed we leave it there, if it is not it has to go.
> This is another holdover from previous patch versions that may be OBE.
See above.
Lorenzo
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