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 08:17:13AM +0100, Yeoreum Yun wrote:
> Hi Jarkko,
> 
> Sorry for late answer.

it's all good, there's been a bug storm so I'm glad that you have not been
around ;-)

BR, Jarkko

> 
> > 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?
> 
> Link: https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/commit/?h=for-next/ffa/updates&id=cc7e8f21b9f0c229d68cf19a837cba82b5ac2d87 [0]
> Link: https://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux.git/commit/?h=for-next/ffa/updates&id=e659fc8e537c7a21d5d693d6f30d8852f2fa8d91 [1]
> 
> -- 
> Sincerely,
> Yeoreum Yun