From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga14.intel.com ([192.55.52.115]:16581 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752838AbeFURNL (ORCPT ); Thu, 21 Jun 2018 13:13:11 -0400 Date: Thu, 21 Jun 2018 20:13:08 +0300 From: Jarkko Sakkinen To: Jason Gunthorpe Cc: Stefan Berger , linux-integrity@vger.kernel.org, zohar@linux.vnet.ibm.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 1/4] tpm: Implement tpm_chip_find() and tpm_chip_put() for other subsystems Message-ID: <20180621171308.GH11859@linux.intel.com> References: <20180620204236.1572523-1-stefanb@linux.vnet.ibm.com> <20180620204236.1572523-2-stefanb@linux.vnet.ibm.com> <20180620205004.GG27445@ziepe.ca> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20180620205004.GG27445@ziepe.ca> Sender: linux-integrity-owner@vger.kernel.org List-ID: On Wed, Jun 20, 2018 at 02:50:04PM -0600, Jason Gunthorpe wrote: > On Wed, Jun 20, 2018 at 04:42:33PM -0400, Stefan Berger wrote: > > Implement tpm_chip_find() for other subsystems to find a TPM chip and > > get a reference to that chip. Once done with using the chip, the reference > > is released using tpm_chip_put(). > > > > Signed-off-by: Stefan Berger > > drivers/char/tpm/tpm-chip.c | 37 +++++++++++++++++++++++++++++++++++++ > > include/linux/tpm.h | 9 +++++++++ > > 2 files changed, 46 insertions(+) > > > > diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c > > index 0a62c19937b6..eaaf41ce73d8 100644 > > +++ b/drivers/char/tpm/tpm-chip.c > > @@ -81,6 +81,43 @@ void tpm_put_ops(struct tpm_chip *chip) > > EXPORT_SYMBOL_GPL(tpm_put_ops); > > > > /** > > + * tpm_chip_put() - Release a ref to the tpm_chip > > + * @chip: Chip to put > > + */ > > +void tpm_chip_put(struct tpm_chip *chip) > > +{ > > + if (chip) > > + put_device(&chip->dev); > > Rarely like to see those if's inside a put function.. Does it actually > help anything? > > Jason The check only helps to hidden regressions here... /Jarkko