From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932595AbdBPPoK (ORCPT ); Thu, 16 Feb 2017 10:44:10 -0500 Received: from smtp11.infineon.com ([217.10.52.105]:47237 "EHLO smtp11.infineon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932359AbdBPPoG (ORCPT ); Thu, 16 Feb 2017 10:44:06 -0500 X-Greylist: delayed 596 seconds by postgrey-1.27 at vger.kernel.org; Thu, 16 Feb 2017 10:44:05 EST X-SBRS: None From: Peter Huewe To: Jarkko Sakkinen CC: Jason Gunthorpe , , , , Alexander Steffen , , Peter Huewe Subject: [PATCH] tpm_tis_core: Choose appropriate timeout for reading burstcount Date: Thu, 16 Feb 2017 15:33:36 +0000 Message-ID: <1487259216-28955-1-git-send-email-peter.huewe@infineon.com> X-Mailer: git-send-email 2.7.4 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [172.29.170.145] X-ClientProxiedBy: MUCSE601.infineon.com (172.23.7.102) To MUCSE612.infineon.com (172.23.7.113) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Alexander Steffen TIS v1.3 for TPM 1.2 and PTP for TPM 2.0 disagree about which timeout value applies to reading a valid burstcount. It is TIMEOUT_D according to TIS, but TIMEOUT_A according to PTP, so choose the appropriate value depending on whether we deal with a TPM 1.2 or a TPM 2.0. This is important since according to the PTP TIMEOUT_D is much smaller than TIMEOUT_A. So the previous implementation could run into timeouts with a TPM 2.0, even though the TPM was behaving perfectly fine. During tpm2_probe TIMEOUT_D will be used even with a TPM 2.0, because TPM_CHIP_FLAG_TPM2 is not yet set. This is fine, since the timeout values will only be changed afterwards by tpm_get_timeouts. Until then TIS_TIMEOUT_D_MAX applies, which is large enough. Cc: stable@vger.kernel.org Fixes: aec04cbdf723 ("tpm: TPM 2.0 FIFO Interface") Signed-off-by: Alexander Steffen Signed-off-by: Peter Huewe --- drivers/char/tpm/tpm_tis_core.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c index c0f296b5d413..fc0e9a2734ed 100644 --- a/drivers/char/tpm/tpm_tis_core.c +++ b/drivers/char/tpm/tpm_tis_core.c @@ -160,8 +160,10 @@ static int get_burstcount(struct tpm_chip *chip) u32 value; /* wait for burstcount */ - /* which timeout value, spec has 2 answers (c & d) */ - stop = jiffies + chip->timeout_d; + if (chip->flags & TPM_CHIP_FLAG_TPM2) + stop = jiffies + chip->timeout_a; + else + stop = jiffies + chip->timeout_d; do { rc = tpm_tis_read32(priv, TPM_STS(priv->locality), &value); if (rc < 0) -- 2.7.4