lkml.org 
[lkml]   [2018]   [Mar]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH 3/5 V2] tpm2: add longer timeouts for creation commands.
From
Date
On Tue, 2018-03-06 at 15:19 +0000, Winkler, Tomas wrote:
> > On Tue, 2018-03-06 at 11:25 +0200, Tomas Winkler wrote:
> > > TPM2_CC_Create(0x153) and TPM2_CC_CreatePrimary (0x131) involve
> > > generation of crypto keys which can be a computationally intensive task.
> > > The timeout is set to 3min.
> > > Rather than increasing default timeout a new constant is added, to not
> > > stall for too long on regular commands failures.
> > >
> > > Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
> >
> > Why are you radically chaging the default timeout? The commit message
> > does not tell anything about that change.
> >
>
> Let me, recheck but it should be same value just converted to msecs.
>
> > Why couldn't we just have two timeouts: one default and one long that
> > would be at least as long as the longest timeout defined in the spec?
>
> I've tried to explain it in the commit message but apparently has failed.
>
> We have a default or undefined which should be the same as it was unless I did
> some silly mistake in conversion to msecs (will check), ass all others are in
> msecs.
> It was 2 min = 2 * 60 * HZ (in jiffies) which would be msecs_to_jiffies(2 * 60
> * 1000 = 120000)
> TPM2_DURATION_DEFAULT = 120000

Aah, of course :-) The problem was that I had somehow a blid spot with
seeing the msec_to_jiffies() conversion.

TPM_NUM_DURATIONS would a better name than TPM_DURATION_MAX because
TPM_DURATION_MAX is easy to confuse with TPM_DURATION_* constants.

/Jarkko

\
 
 \ /
  Last update: 2018-03-10 12:21    [W:0.167 / U:0.400 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site