linux-kernel - Re: [PATCH] tpm: moves the delay_msec increment after sleep in tpm

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Message-ID: <d7989ecd5e2d6463636ba291128b525b89cb2521.camel@linux.intel.com>
Date:   Tue, 10 Apr 2018 15:31:09 +0300
From:   Jarkko Sakkinen <jarkko.sakkinen@...ux.intel.com>
To:     Mimi Zohar <zohar@...ux.vnet.ibm.com>,
        Nayna Jain <nayna@...ux.vnet.ibm.com>
Cc:     linux-integrity@...r.kernel.org,
        linux-security-module@...r.kernel.org,
        linux-kernel@...r.kernel.org, peterhuewe@....de,
        tpmdd@...horst.net, jgunthorpe@...idianresearch.com
Subject: Re: [PATCH] tpm: moves the delay_msec increment after sleep in
 tpm_transmit()

On Mon, 2018-04-09 at 10:29 -0400, Mimi Zohar wrote:
> On Sat, 2018-04-07 at 13:36 +0300, Jarkko Sakkinen wrote:
> > On Fri, Apr 06, 2018 at 02:03:37PM +0530, Nayna Jain wrote:
> > > On 04/05/2018 03:42 PM, Jarkko Sakkinen wrote:
> > > > On Mon, Apr 02, 2018 at 09:50:06PM +0530, Nayna Jain wrote:
> > > > > Commit e2fb992d82c6 ("tpm: add retry logic") introduced a new loop to
> > > > > handle the TPM2_RC_RETRY error. The loop retries the command after
> > > > > sleeping for the specified time, which is incremented exponentially in
> > > > > every iteration. This patch fixes the initial sleep to be the default
> > > > > sleep time.
> > > > 
> > > > I think I understand the code change but do not understand what the
> > > > long description.
> > > 
> > > It tells that the first sleep is delay_msec * 2 and not delay_msec.
> > 
> > So the problem is that the loop doubles the time before sleeping
> > for the first time. This is missing from the description. Please
> > refine it in some way.
> 
> Sure, how about replacing the last line of the patch description with:
>     Unfortunately, the loop doubles the time before sleeping, causing the
>     initial sleep to be doubled.  This patch fixes the initial sleep time.
> 
> If this change is acceptable, do you want to make the change or should Nayna
> repost the patch?

No need. I'll move on to testing.

/Jarkko