lkml.org 
[lkml]   [2017]   [Oct]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH v3 4/5] tpm: reduce tpm_msleep() time in get_burstcount()
From
Date


On 10/12/2017 04:48 PM, Jarkko Sakkinen wrote:
> On Wed, Oct 04, 2017 at 06:29:23AM -0400, Nayna Jain wrote:
>> 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 5msec 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 <nayna@linux.vnet.ibm.com>
>> Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
>> ---
>> 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 224842e06105..826a0b9c9201 100644
>> --- a/drivers/char/tpm/tpm_tis_core.c
>> +++ b/drivers/char/tpm/tpm_tis_core.c
>> @@ -226,7 +226,7 @@ static int get_burstcount(struct tpm_chip *chip)
>> burstcnt = (value >> 8) & 0xFFFF;
>> if (burstcnt)
>> return burstcnt;
>> - tpm_msleep(TPM_TIMEOUT);
>> + tpm_msleep(TPM_POLL_SLEEP);
>> } while (time_before(jiffies, stop));
>> return -EBUSY;
>> }
>> --
>> 2.13.3
>>
> Would it make sense to squash this to 3/5 and merge the commit
> messages?
Yeah.. it sounds reasonable.. both are reducing the sleep delay time for
same purpose, just in different functions.

Thanks & Regards,
    - Nayna

>
> /Jarkko
>

\
 
 \ /
  Last update: 2017-10-12 15:15    [W:0.048 / U:2.492 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site