From patchwork Wed Jul 20 02:34:19 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrey Pronin X-Patchwork-Id: 9238679 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 39752600CB for ; Wed, 20 Jul 2016 02:34:35 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2B8502624C for ; Wed, 20 Jul 2016 02:34:35 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 2074D268AE; Wed, 20 Jul 2016 02:34:35 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from lists.sourceforge.net (lists.sourceforge.net [216.34.181.88]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id D7F2C2793A for ; Wed, 20 Jul 2016 02:34:33 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=sfs-ml-1.v29.ch3.sourceforge.com) by sfs-ml-1.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1bPhLD-000132-Ap; Wed, 20 Jul 2016 02:34:31 +0000 Received: from sog-mx-2.v43.ch3.sourceforge.com ([172.29.43.192] helo=mx.sourceforge.net) by sfs-ml-1.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1bPhLC-00012v-0Z for tpmdd-devel@lists.sourceforge.net; Wed, 20 Jul 2016 02:34:30 +0000 Received-SPF: pass (sog-mx-2.v43.ch3.sourceforge.com: domain of chromium.org designates 209.85.192.176 as permitted sender) client-ip=209.85.192.176; envelope-from=apronin@chromium.org; helo=mail-pf0-f176.google.com; Received: from mail-pf0-f176.google.com ([209.85.192.176]) by sog-mx-2.v43.ch3.sourceforge.com with esmtps (TLSv1:AES128-SHA:128) (Exim 4.76) id 1bPhLB-0002hL-7X for tpmdd-devel@lists.sourceforge.net; Wed, 20 Jul 2016 02:34:29 +0000 Received: by mail-pf0-f176.google.com with SMTP id p64so13584513pfb.1 for ; Tue, 19 Jul 2016 19:34:29 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:in-reply-to:references; bh=e/Y1h9MxNVJ53v90p0MPNV9wGCDyjf6TURtImHpWJUg=; b=E/PTqowgV+5XQD8RO5NLBd5oOqp1+qh2RBGSsLTWJozZl9uvh2HNa45WUL1Sze8FvE MNUV2hofRHLHoev2Gxg83ugOfJvJnnvCqSIe+gG2qIT53PxqTM66D3et5YSmRviBSqf4 7wTxWReZKL+ATV16XqEmFabg3EdJyQn8CWk/W3g+wxY5m4TCU+/vF4sXyVu5EjY/gHqP SIfE9UnDhTSSSRvlZKU0iA77xq1RipHq1XmQaEe9ax+5XdU++br2uas6B4cIJM3PQJNg 7HgO3bAXweEuVGaEhScaWYAYb0xB8W10wCq6gj38OzF86mlBHaTkK4+omscxgCgFHYVc X++g== X-Gm-Message-State: ALyK8tLKJXIOuUxWg+MMWTA2yD0wNg+U14Lo82+TTxmw1KxiDhoopDFHi5OakHWhZ+6SDFPs X-Received: by 10.98.21.131 with SMTP id 125mr60824234pfv.92.1468982063521; Tue, 19 Jul 2016 19:34:23 -0700 (PDT) Received: from apronin0.mtv.corp.google.com ([172.22.64.136]) by smtp.gmail.com with ESMTPSA id x184sm324300pfd.70.2016.07.19.19.34.22 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Tue, 19 Jul 2016 19:34:23 -0700 (PDT) From: Andrey Pronin To: Jarkko Sakkinen Date: Tue, 19 Jul 2016 19:34:19 -0700 Message-Id: X-Mailer: git-send-email 2.8.0.rc3.226.g39d4020 In-Reply-To: References: <1468546745-14646-1-git-send-email-apronin@chromium.org> In-Reply-To: References: <1468546745-14646-1-git-send-email-apronin@chromium.org> X-Headers-End: 1bPhLB-0002hL-7X Cc: Christophe Ricard , linux-kernel@vger.kernel.org, tpmdd-devel@lists.sourceforge.net Subject: [tpmdd-devel] [PATCH v2 1/2] tpm_tis_core: add optional max xfer size check X-BeenThere: tpmdd-devel@lists.sourceforge.net X-Mailman-Version: 2.1.9 Precedence: list List-Id: Tpm Device Driver maintainance List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: tpmdd-devel-bounces@lists.sourceforge.net X-Virus-Scanned: ClamAV using ClamSMTP If tpm reports a bigger burstcnt than allowed by the physical protocol, re-query the burstcnt and correct, if needed, if still too large. In practice, seen in case of xfer issues (e.g. in spi interface case, lost header causing flow control issues and wrong values returned on read from TPM_STS). Without catching, causes the physical layer to reject xfer, while is easily preventable by re-querying TPM_STS. Signed-off-by: Andrey Pronin --- drivers/char/tpm/tpm_tis_core.c | 18 ++++++++++++++++-- drivers/char/tpm/tpm_tis_core.h | 1 + 2 files changed, 17 insertions(+), 2 deletions(-) diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c index d66f51b..ffc1acb 100644 --- a/drivers/char/tpm/tpm_tis_core.c +++ b/drivers/char/tpm/tpm_tis_core.c @@ -158,6 +158,7 @@ static int get_burstcount(struct tpm_chip *chip) unsigned long stop; int burstcnt, rc; u32 value; + bool retry_burstcnt = false; /* wait for burstcount */ /* which timeout value, spec has 2 answers (c & d) */ @@ -168,8 +169,21 @@ static int get_burstcount(struct tpm_chip *chip) return rc; burstcnt = (value >> 8) & 0xFFFF; - if (burstcnt) - return burstcnt; + if (burstcnt) { + /* If burstcnt is larger than max allowed xfer + * size, retry once - may be a glitch. Return + * max_xfer_size on the 2nd try to avoid being + * stuck forever. + */ + if ((priv->phy_ops->max_xfer_size == 0) || + (burstcnt <= priv->phy_ops->max_xfer_size)) + return burstcnt; + if (retry_burstcnt) + return priv->phy_ops->max_xfer_size; + dev_warn(&chip->dev, + "Bad burstcnt read: %d\n", burstcnt); + retry_burstcnt = true; + } msleep(TPM_TIMEOUT); } while (time_before(jiffies, stop)); return -EBUSY; diff --git a/drivers/char/tpm/tpm_tis_core.h b/drivers/char/tpm/tpm_tis_core.h index 9191aab..58e8b14 100644 --- a/drivers/char/tpm/tpm_tis_core.h +++ b/drivers/char/tpm/tpm_tis_core.h @@ -102,6 +102,7 @@ struct tpm_tis_phy_ops { int (*read16)(struct tpm_tis_data *data, u32 addr, u16 *result); int (*read32)(struct tpm_tis_data *data, u32 addr, u32 *result); int (*write32)(struct tpm_tis_data *data, u32 addr, u32 src); + u16 max_xfer_size; }; static inline int tpm_tis_read_bytes(struct tpm_tis_data *data, u32 addr,