| Message ID | 20250414145235.938924-1-stuart.yoder@arm.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | tpm_crb: ffa_tpm: return errors from interface functions if no ffa-crb driver | expand |
On Mon, Apr 14, 2025 at 09:52:35AM -0500, Stuart Yoder wrote: > If ACPI advertises an FF-A based TPM but the tpm_crb_ffa driver is not > enabled via Kconfig, inline stub versions of the interface functions > are used. These functions incorrectly return 0, which indicates success. > The result is that the tpm_crb probe function continues execution and > eventually detects a timeout at the TPM. > > Change the inline functions to return errors, so that probe() sees that > tpm_crb_ffa is not present and aborts the probe. > LGTM, Acked-by: Sudeep Holla <sudeep.holla@arm.com>
diff --git a/drivers/char/tpm/tpm_crb_ffa.h b/drivers/char/tpm/tpm_crb_ffa.h index 645c41ede10ed..c006403e2f14b 100644 --- a/drivers/char/tpm/tpm_crb_ffa.h +++ b/drivers/char/tpm/tpm_crb_ffa.h @@ -14,9 +14,9 @@ int tpm_crb_ffa_init(void); int tpm_crb_ffa_get_interface_version(u16 *major, u16 *minor); int tpm_crb_ffa_start(int request_type, int locality); #else -static inline int tpm_crb_ffa_init(void) { return 0; } -static inline int tpm_crb_ffa_get_interface_version(u16 *major, u16 *minor) { return 0; } -static inline int tpm_crb_ffa_start(int request_type, int locality) { return 0; } +static inline int tpm_crb_ffa_init(void) { return -ENODEV; } +static inline int tpm_crb_ffa_get_interface_version(u16 *major, u16 *minor) { return -ENODEV; } +static inline int tpm_crb_ffa_start(int request_type, int locality) { return -ENODEV; } #endif #define CRB_FFA_START_TYPE_COMMAND 0
If ACPI advertises an FF-A based TPM but the tpm_crb_ffa driver is not enabled via Kconfig, inline stub versions of the interface functions are used. These functions incorrectly return 0, which indicates success. The result is that the tpm_crb probe function continues execution and eventually detects a timeout at the TPM. Change the inline functions to return errors, so that probe() sees that tpm_crb_ffa is not present and aborts the probe. Signed-off-by: Stuart Yoder <stuart.yoder@arm.com> --- drivers/char/tpm/tpm_crb_ffa.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)