* H. Peter Anvin hpa@zytor.com wrote:
Just to make it clear: the patch is correct, the shortcoming is in the description.
I would say that Xin's description, although perhaps excessively brief, is correct from the *hardware* point of view, whereas Rafael adds the much needed *software* perspective.
This part of the -v1 patch was a bit misleading to me:
Due to changes in the kernel text and data mappings, the FRED MSRs must be reinitialized.
... as it suggests that the FRED MSRs will change from before the suspend - while they don't.
What this sentence meant is that FRED MSRs set up by the intermediate *kexec kernel* are incorrect and must be reinitialized again to reconstruct the pre-hibernation state. Ie. there's 3 FRED setup states: pre-S4, kexec and post-S4, where pre-S4 == post-S4. Right?
I think the description and comments in the -v2 patch are better in this regard.
Thanks,
Ingo