Re: [PATCH v4 3/3] tpm: tpm_crb_ffa: revert defered_probed when tpm_crb_ffa is built-in

[Jarkko Sakkinen <jarkko@kernel.org>]

On Mon, Jun 01, 2026 at 11:01:48AM +0100, Yeoreum Yun wrote:
> > On Mon, Jun 01, 2026 at 08:17:13AM +0100, Yeoreum Yun wrote:
> > > Hi Jarkko,
> > > 
> > > Sorry for late answer.
> > > 
> > > > On Mon, May 25, 2026 at 08:54:04AM +0100, Yeoreum Yun wrote:
> > > > > commit 746d9e9f62a6 ("tpm: tpm_crb_ffa: try to probe tpm_crb_ffa when it's build_in")
> > > > > probe tpm_crb_ffa forcefully when it's built-in to integrate with IMA.
> > > > > 
> > > > > However, IMA now provides the IMA_INIT_LATE_SYNC build option, which
> > > > > initialises IMA at the late_initcall_sync level, so this change is no
> > > > > longer required.
> > > > > 
> > > > > Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
> > > > > ---
> > > > >  drivers/char/tpm/tpm_crb_ffa.c | 18 +++---------------
> > > > >  1 file changed, 3 insertions(+), 15 deletions(-)
> > > > > 
> > > > > diff --git a/drivers/char/tpm/tpm_crb_ffa.c b/drivers/char/tpm/tpm_crb_ffa.c
> > > > > index 99f1c1e5644b..025c4d4b17ca 100644
> > > > > --- a/drivers/char/tpm/tpm_crb_ffa.c
> > > > > +++ b/drivers/char/tpm/tpm_crb_ffa.c
> > > > > @@ -177,23 +177,13 @@ static int tpm_crb_ffa_to_linux_errno(int errno)
> > > > >   */
> > > > >  int tpm_crb_ffa_init(void)
> > > > >  {
> > > > > -	int ret = 0;
> > > > > -
> > > > > -	if (!IS_MODULE(CONFIG_TCG_ARM_CRB_FFA)) {
> > > > > -		ret = ffa_register(&tpm_crb_ffa_driver);
> > > > > -		if (ret) {
> > > > > -			tpm_crb_ffa = ERR_PTR(-ENODEV);
> > > > > -			return ret;
> > > > > -		}
> > > > > -	}
> > > > > -
> > > > >  	if (!tpm_crb_ffa)
> > > > > -		ret = -ENOENT;
> > > > > +		return -ENOENT;
> > > > >  
> > > > >  	if (IS_ERR_VALUE(tpm_crb_ffa))
> > > > > -		ret = -ENODEV;
> > > > > +		return -ENODEV;
> > > > >  
> > > > > -	return ret;
> > > > > +	return 0;
> > > > >  }
> > > > >  EXPORT_SYMBOL_GPL(tpm_crb_ffa_init);
> > > > >  
> > > > > @@ -405,9 +395,7 @@ static struct ffa_driver tpm_crb_ffa_driver = {
> > > > >  	.id_table = tpm_crb_ffa_device_id,
> > > > >  };
> > > > >  
> > > > > -#ifdef MODULE
> > > > >  module_ffa_driver(tpm_crb_ffa_driver);
> > > > > -#endif
> > > > >  
> > > > >  MODULE_AUTHOR("Arm");
> > > > >  MODULE_DESCRIPTION("TPM CRB FFA driver");
> > > > > -- 
> > > > > LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}
> > > > > 
> > > > 
> > > > How we would sync up this patch? Through which tree etc.
> > > 
> > > IMHO, the IMA relevant thing would be into IMA tree,
> > > However I think this patch would be much easier to sync into Sudeep's
> > > FF-A tree where ff-a initilisation is reverted to device_initcall
> > > unless you're uncomfortable.
> > > 
> > > For this, It might be better to split this patch from this series
> > > since by above and defer probe of ff-a would make a register failure
> > > of registering tpm_crb_ffa driver which is built-in.
> > > 
> > > @Sudeep what do you think?
> > > 
> > 
> > IIRC, there is/was no dependency between these and FF-A patches that are
> > queued in terms of build. I agree there may be dependency to get all the
> > functionality but we can resort to linux-next for that. FF-A is not enabled
> > in the defconfig, so anyone working on FF-A + TPM must enable then and can
> > rely on -next IMHO.
> > 
> > That said, I have already sent PR for FF-A to SoC team and it is already
> > queued for v7.2. I don't have any other plans unless they are fixes.
> 
> Thanks. Then I think it's enough to merge this patch to TPM tree
> when this patchset is approved once.

Oops, sorry I've forgot to tag this although I've mentally accepted
this (which does not unfortunately help move things forward):

It's probably better just put SOB to the tail, or least messiest
I think:

Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>

> 
> -- 
> Sincerely,
> Yeoreum Yun

BR, Jarkko