From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nayna Jain Subject: [PATCH v2 3/4] tpm: reduce tpm_msleep() time in get_burstcount() Date: Wed, 6 Sep 2017 08:56:38 -0400 Message-ID: <20170906125643.5070-4-nayna@linux.vnet.ibm.com> References: <20170906125643.5070-1-nayna@linux.vnet.ibm.com> Return-path: In-Reply-To: <20170906125643.5070-1-nayna@linux.vnet.ibm.com> Sender: owner-linux-security-module@vger.kernel.org To: tpmdd-devel@lists.sourceforge.net Cc: peterhuewe@gmx.de, tpmdd@selhorst.net, jarkko.sakkinen@linux.intel.com, jgunthorpe@obsidianresearch.com, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, linux-ima-devel@lists.sourceforge.net, patrickc@us.ibm.com, Nayna Jain List-Id: tpmdd-devel@lists.sourceforge.net Currently, get_burstcount() function sleeps for 5msec in a loop before retrying for next query to burstcount. However, if it takes lesser time for TPM to return, this 5 msec delay is longer than necessary. This patch replaces the tpm_msleep time from 5msec to 1msec. After this change, performance on a TPM 1.2 with an 8 byte burstcount for 1000 extends improved from ~10sec to ~9sec. Signed-off-by: Nayna Jain Acked-by: Mimi Zohar --- drivers/char/tpm/tpm_tis_core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c index d1eab29cb447..d710bbc4608b 100644 --- a/drivers/char/tpm/tpm_tis_core.c +++ b/drivers/char/tpm/tpm_tis_core.c @@ -169,7 +169,7 @@ static int get_burstcount(struct tpm_chip *chip) burstcnt = (value >> 8) & 0xFFFF; if (burstcnt) return burstcnt; - tpm_msleep(TPM_TIMEOUT); + tpm_msleep(1); } while (time_before(jiffies, stop)); return -EBUSY; } -- 2.13.3