Hi Jarkko, > On Wed, Jun 18, 2025 at 11:23:00AM +0100, Yeoreum Yun wrote: > > To ensure the TPM device operating over the FF-A protocol with > > the CRB interface is probed before IMA initialization, > > the following conditions must be met: > > > > 1. The corresponding ffa_device must be registered, > > which is done via ffa_init(). > > > > 2. The tpm_crb_driver must successfully probe this device via > > tpm_crb_ffa_init(). > > > > 3. The tpm_crb driver using CRB over FF-A can then > > be probed successfully. (See crb_acpi_add() and > > tpm_crb_ffa_init() for reference.) > > > > Unfortunately, ffa_init(), tpm_crb_ffa_init(), and crb_acpi_driver_init() > > are > > all registered with device_initcall, which means crb_acpi_driver_init() may > > be invoked before ffa_init() and tpm_crb_ffa_init() are completed. > > I get the ffa_init() part i.e, moving it earlier. However for > tpm_crb_ffa_init() and crb_acpi_driver_init(), modules.dep > takes care that they are loaded in order. > For IMA you will need the driver as built-in but that should > be handled via kernel config, not via code changes.
In the case of "module" built, it's true. However what I tell here is when "tpm_crb" and "tpm_crb_ffa" is built as "built-in" in this case, it couldn't make a "dependency" between the same initcall level: here is the case of this. 0000000000000888 l .initcall6.init>-------0000000000000000 crb_acpi_driver_init 000000000000088c l .initcall6.init>-------0000000000000000 tpm_crb_ffa_driver_init in this case, wihtout code change, the crb_acpi_driver_init() is failed since tpm_crb_ffa_driver_init() is called later. and this couldn't be solved with kconfig -- ARM_FFA_TRANSPORT=y && CONFIG_TCG_CRB=y && CONFIG_TCG_CRB_FFA=y. The Patch #2 is to proing the tpm_crb_ffa as part of crb_acpi_driver_init() when TPM uses method ARM-FFA. If there's another suggestion, let me know please. Thanks -- Sincerely, Yeoreum Yun
