Dear Hao,
Thank you for the reply.
Am 12.09.20 um 10:10 schrieb Hao Wu:
Thanks for quick responses over this report.
Thank you for the quick follow-up.
Hao, I wouldn’t expect a longer timeout causing the TPM to be
queried less frequently, but I do not know the code well.
From our understanding, the TPM queries might be retried due to some
reason, increase timeout 3x would lower the query frequency to 1/3.
The explanation might be wrong, but the fact looks like the timeout
matters. Unfortunately, engineers from Rubrik are not experts over
the TPM driver code neither :(
Be careful about making this a global change. It could reduce
the TPM performance by 3x. We don't want to affect all TPMs to
fix a bug in an old TPM 1.2 chip from one vendor.
Linux has a no regression policy, so the performance penalty
wouldn’t matter. Unfortunately, the regression was only noticed
several years after being introduced in Linux v4.14-rc2.
So does that mean we are good to apply the global change ? Or we need
to discuss about the actual fix further?
To get a fix into the stable series, it first needs to be applied to the
master branch. I guess you tested also with Linux master, right?
Please add the explanation from your email to Greg into the git commit
message, format the patch with `git format-patch -1 -o outgoing` and
send it with `git send-email outgoing/*` to the addresses listed for the
subsystem in `MAINTAINERS` and the people listed in the commit
introducing the regression.
Then it can be properly reviewed and discussed.
Kind regards,
Paul
