Hi Stefan,
On 22.12.21 at 05:53, Stefan Berger wrote:
drivers/char/tpm/tpm-chip.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-)
diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c index ddaeceb7e109..7960da490e72 100644 --- a/drivers/char/tpm/tpm-chip.c +++ b/drivers/char/tpm/tpm-chip.c @@ -474,13 +474,19 @@ static void tpm_del_char_device(struct tpm_chip *chip) /* Make the driver uncallable. */ down_write(&chip->ops_sem); - if (chip->flags & TPM_CHIP_FLAG_TPM2) { - if (!tpm_chip_start(chip)) { - tpm2_shutdown(chip, TPM2_SU_CLEAR); - tpm_chip_stop(chip); + /* Check if chip->ops is still valid: In case that the controller + * drivers shutdown handler unregisters the controller in its + * shutdown handler we are called twice and chip->ops to NULL. + */ + if (chip->ops) { + if (chip->flags & TPM_CHIP_FLAG_TPM2) { + if (!tpm_chip_start(chip)) { + tpm2_shutdown(chip, TPM2_SU_CLEAR); + tpm_chip_stop(chip); + } } + chip->ops = NULL; } - chip->ops = NULL; up_write(&chip->ops_sem); } base-commit: a7904a538933c525096ca2ccde1e60d0ee62c08e
Fixes: 39d0099f9439 ("powerpc/pseries: Add shutdown() to vio_driver and vio_bus")
Reviewed-by: Stefan Berger stefanb@linux.ibm.com
Tested-by: Stefan Berger stefanb@linux.ibm.com
Thanks a lot for testing this.
Best regards, Lino