Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753923AbdDENlJ (ORCPT ); Wed, 5 Apr 2017 09:41:09 -0400 Received: from mga09.intel.com ([134.134.136.24]:24409 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754571AbdDENhj (ORCPT ); Wed, 5 Apr 2017 09:37:39 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.36,278,1486454400"; d="scan'208";a="1131351848" Date: Wed, 5 Apr 2017 16:37:24 +0300 From: Jarkko Sakkinen To: Peter Huewe Cc: Enric Balletbo i Serra , Andrew Lunn , tpmdd-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, wsa@the-dreams.de, Bryan Freed Subject: Re: [PATCH v3] tpm: Apply a sane minimum adapterlimit value for retransmission. Message-ID: <20170405133724.gfmyopgtpbrgycxl@intel.com> References: <20170328152938.14539-1-enric.balletbo@collabora.com> <20170405090327.pssnm3mjcpajpoy6@intel.com> <384D02FC-BCCF-45F0-896D-058326EC6783@gmx.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <384D02FC-BCCF-45F0-896D-058326EC6783@gmx.de> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: Mutt/1.6.2-neo (2016-08-21) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5373 Lines: 155 On Wed, Apr 05, 2017 at 12:05:32PM +0200, Peter Huewe wrote: > > > Am 5. April 2017 11:03:27 MESZ schrieb Jarkko Sakkinen : > >On Tue, Mar 28, 2017 at 05:29:38PM +0200, Enric Balletbo i Serra wrote: > >> From: Bryan Freed > >> > >> When the I2C Infineon part is attached to an I2C adapter that imposes > >> a size limitation, large requests will fail with -EOPNOTSUPP. Retry > >> them with a sane minimum size without re-issuing the 0x05 command > >> as this appears to occasionally put the TPM in a bad state. > >> > >> Signed-off-by: Bryan Freed > >> [rework the patch to adapt to the feedback received] > >> Signed-off-by: Enric Balletbo i Serra > >> --- > >> This is a reworked version of the original patch based on the > >> suggestion made by Wolfram Sang to simply fall back to a sane minimum > >> when the maximum fails. > >> > >> Changes since v2: > >> - Do not remove faster transfers when chip is SLB9645 (Peter Huewe) > >> - Remember the adapterlimit length once it fails to not generate > >extra > >> i2c core messages (suggested by Andrew Lunn) > >> Changes since v1: > >> - Check the correct return value (-EOPNOTSUPP instead of -EINVAL) > >> - Fall back len to I2C_SMBUS_BLOCK_MAX if fails. > >> > >> drivers/char/tpm/tpm_i2c_infineon.c | 76 > >+++++++++++++++++++++++++++---------- > >> 1 file changed, 56 insertions(+), 20 deletions(-) > >> > >> diff --git a/drivers/char/tpm/tpm_i2c_infineon.c > >b/drivers/char/tpm/tpm_i2c_infineon.c > >> index 62ee44e..fdefcdb 100644 > >> --- a/drivers/char/tpm/tpm_i2c_infineon.c > >> +++ b/drivers/char/tpm/tpm_i2c_infineon.c > >> @@ -70,6 +70,7 @@ struct tpm_inf_dev { > >> u8 buf[TPM_BUFSIZE + sizeof(u8)]; /* max. buffer size + addr */ > >> struct tpm_chip *chip; > >> enum i2c_chip_type chip_type; > >> + unsigned int adapterlimit; > >> }; > >> > >> static struct tpm_inf_dev tpm_dev; > >> @@ -111,6 +112,7 @@ static int iic_tpm_read(u8 addr, u8 *buffer, > >size_t len) > >> > >> int rc = 0; > >> int count; > >> + unsigned int msglen = len; > >> > >> /* Lock the adapter for the duration of the whole sequence. */ > >> if (!tpm_dev.client->adapter->algo->master_xfer) > >> @@ -131,27 +133,61 @@ static int iic_tpm_read(u8 addr, u8 *buffer, > >size_t len) > >> usleep_range(SLEEP_DURATION_LOW, SLEEP_DURATION_HI); > >> } > >> } else { > >> - /* slb9635 protocol should work in all cases */ > >> - for (count = 0; count < MAX_COUNT; count++) { > >> - rc = __i2c_transfer(tpm_dev.client->adapter, &msg1, 1); > >> - if (rc > 0) > >> - break; /* break here to skip sleep */ > >> - > >> - usleep_range(SLEEP_DURATION_LOW, SLEEP_DURATION_HI); > >> - } > >> - > >> - if (rc <= 0) > >> - goto out; > >> - > >> - /* After the TPM has successfully received the register address > >> - * it needs some time, thus we're sleeping here again, before > >> - * retrieving the data > >> + /* Expect to send one command message and one data message, but > >> + * support looping over each or both if necessary. > >> */ > >> - for (count = 0; count < MAX_COUNT; count++) { > >> - usleep_range(SLEEP_DURATION_LOW, SLEEP_DURATION_HI); > >> - rc = __i2c_transfer(tpm_dev.client->adapter, &msg2, 1); > >> - if (rc > 0) > >> - break; > >> + while (len > 0) { > >> + /* slb9635 protocol should work in all cases */ > >> + for (count = 0; count < MAX_COUNT; count++) { > >> + rc = __i2c_transfer(tpm_dev.client->adapter, > >> + &msg1, 1); > >> + if (rc > 0) > >> + break; /* break here to skip sleep */ > >> + > >> + usleep_range(SLEEP_DURATION_LOW, > >> + SLEEP_DURATION_HI); > >> + } > >> + > >> + if (rc <= 0) > >> + goto out; > >> + > >> + /* After the TPM has successfully received the register > >> + * address it needs some time, thus we're sleeping here > >> + * again, before retrieving the data > >> + */ > >> + for (count = 0; count < MAX_COUNT; count++) { > >> + if (tpm_dev.adapterlimit) { > >> + msglen = min_t(unsigned int, > >> + tpm_dev.adapterlimit, > >> + len); > >> + msg2.len = msglen; > >> + } > >> + usleep_range(SLEEP_DURATION_LOW, > >> + SLEEP_DURATION_HI); > >> + rc = __i2c_transfer(tpm_dev.client->adapter, > >> + &msg2, 1); > >> + if (rc > 0) { > >> + /* Since len is unsigned, make doubly > >> + * sure we do not underflow it. > >> + */ > >> + if (msglen > len) > >> + len = 0; > >> + else > >> + len -= msglen; > >> + msg2.buf += msglen; > >> + break; > >> + } > >> + /* If the I2C adapter rejected the request (e.g > >> + * when the quirk read_max_len < len) fall back > >> + * to a sane minimum value and try again. > >> + */ > >> + if (rc == -EOPNOTSUPP) > >> + tpm_dev.adapterlimit = > >> + I2C_SMBUS_BLOCK_MAX; > >> + } > >> + > >> + if (rc <= 0) > >> + goto out; > >> } > >> } > >> > >> -- > >> 2.9.3 > >> > > > >Reviewed-by: Jarkko Sakkinen > > > >Peter, Andrew, anyone: Tested-by? > > > > Not yet, I'll put it on my list to test. > Hopefully by next tuesday. > Peter Ok, thanks. I can push this to my master branch if that would help to ease the testig? /Jarkko