Re: [PATCH] tpm: tis: Increase the default for timeouts B and C

[Jarkko Sakkinen <jarkko@kernel.org>]

On Fri, Apr 04, 2025 at 10:31:18AM +0100, Jonathan McDowell wrote:
> On Fri, Apr 04, 2025 at 11:10:12AM +0300, Jarkko Sakkinen wrote:
> > On Fri, Apr 04, 2025 at 09:51:29AM +0200, Michal Suchánek wrote:
> > > On Thu, Apr 03, 2025 at 09:43:19PM +0100, Jonathan McDowell wrote:
> > > > On Thu, Apr 03, 2025 at 09:45:21PM +0300, Jarkko Sakkinen wrote:
> > > > > On Wed, Apr 02, 2025 at 06:45:40PM +0100, Jonathan McDowell wrote:
> > > > > > On Wed, Apr 02, 2025 at 07:21:30PM +0200, Michal Suchanek wrote:
> > > > > > > With some Infineon chips the timeouts in tpm_tis_send_data (both B and
> > > > > > > C) can reach up to about 2250 ms.
> > > > > > >
> > > > > > > Extend the timeout duration to accommodate this.
> > > > > >
> > > > > > The problem here is the bump of timeout_c is going to interact poorly with
> > > > > > the Infineon errata workaround, as now we'll wait 4s instead of 200ms to
> > > > > > detect the stuck status change.
> > > > > >
> > > > > > (Also shouldn't timeout_c already end up as 750ms, as it's
> > > > > > max(TIS_SHORT_TIMEOUT, TPM2_TIMEOUT_C), and TIS_SHORT_TIMEOUT is 750 vs 200
> > > > > > for TPM2_TIMEOUT_C? That doesn't seem to be borne out by your logs, nor my
> > > > > > results.)
> > > > >
> > > > > Just noticed that the commit did not end up having fixes etc. tags:
> > > > >
> > > > > https://web.git.kernel.org/pub/scm/linux/kernel/git/jarkko/linux-tpmdd.git/commit/?id=de9e33df7762abbfc2a1568291f2c3a3154c6a9d
> > > > >
> > > > > Should we forward to stable?
> > > >
> > > > It's a TPM bug rather than a kernel issue, so I don't think there's a valid
> > > > Fixes: for it, but it's certainly stable material in my mind.
> > > 
> > > In the more general sense of Fixes: indicating where the fix is
> > > applicable it would be any kernel that supports TPM2.
> > 
> > I tried applying the patch on 6.1-stable:
> > 
> > ~/work/kernel.org/stable/linux tags/v6.1.132
> > $ git am -3 ~/Downloads/infineon.patch
> > Applying: tpm, tpm_tis: Workaround failed command reception on Infineon devices
> > Using index info to reconstruct a base tree...
> > M	drivers/char/tpm/tpm_tis_core.c
> > M	drivers/char/tpm/tpm_tis_core.h
> > M	include/linux/tpm.h
> > Falling back to patching base and 3-way merge...
> > Auto-merging include/linux/tpm.h
> > Auto-merging drivers/char/tpm/tpm_tis_core.h
> > Auto-merging drivers/char/tpm/tpm_tis_core.c
> > 
> > If no counter-opinions, I'd add:
> > 
> > stable@vger.kernel.org # v6.1+
> > 
> > I based this on Bookworm kernel.
> 
> It looks like Sasha has already autoselected it for 6.1, 6.6, 6.12, 6.13 +
> 6.14.

Right! I can see also those mails, and exactly the version range I would
have proposed :-) Perfect, thanks Sasha!

> 
> J.
> 
> -- 
> How does it work?  I don't know but it does!
> This .sig brought to you by the letter R and the number 21
> Product of the Republic of HuggieTag
> 

BR, Jarkko