Possible regression caused by commit 1bd047be37d9 ("tpm_crb: Use devm_ioremap_resource")

Hi, Jason,

we got a bug report complaining that the system can not enter deeper package c-states than pc2, and the git bisect result points to commit 1bd047be37d9 ("tpm_crb: Use devm_ioremap_resource").

can you take a look at this issue?

Bugzilla link: https://bugzilla.kernel.org/show_bug.cgi?id=118451

thanks,
rui

The tagged commit basically swiches devm_ioremap_nocache for devm_ioremap_resource - AFAIK the only external difference being that the TPM driver is now part of the resource tree.

I didn't think resource tree interacted with Intel PM at all?

One thing we know about is that the TPM driver fails to load on some systems due to resource conflicts. Is it possible Yrjan's is seeing TPM load failures in one kernel? Presumably not loading the tpm driver would impact PM somehow??

I recommend checking for the issue solved in this patch:

commit 422eac3f7deae34dbaffd08e03e27f37a5394a56

Author: Jarkko Sakkinen <[email protected]>
Date:   Tue Apr 19 12:54:18 2016 +0300

tpm_crb: fix mapping of the buffers

On my Lenovo x250 the following situation occurs:

[18697.813871] tpm_crb MSFT0101:00: can't request region for resource [mem 0xacdff080-0xacdfffff]

Jason