tpm_tis: Clean up locality release
authorJames Bottomley <James.Bottomley@HansenPartnership.com>
Thu, 1 Oct 2020 18:09:22 +0000 (11:09 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 4 Mar 2021 10:38:28 +0000 (11:38 +0100)
commitd65aef25464f7615d5d5229c2c5b69d1cae68b7a
treebe93c69001a3da652b196f7f5392bd4d86a090a4
parenta1710b067ec9cd85f45bcd649dafd6337fefdf85
tpm_tis: Clean up locality release

commit e42acf104d6e0bd7ccd2f09103d5be5e6d3c637c upstream.

The current release locality code seems to be based on the
misunderstanding that the TPM interrupts when a locality is released:
it doesn't, only when the locality is acquired.

Furthermore, there seems to be no point in waiting for the locality to
be released.  All it does is penalize the last TPM user.  However, if
there's no next TPM user, this is a pointless wait and if there is a
next TPM user, they'll pay the penalty waiting for the new locality
(or possibly not if it's the same as the old locality).

Fix the code by making release_locality as simple write to release
with no waiting for completion.

Cc: stable@ger.kernel.org
Fixes: 33bafe90824b ("tpm_tis: verify locality released before returning from release_locality")
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/char/tpm/tpm_tis_core.c