| Message ID | 20220601083810.330809-1-stefan.mahnke-hartmann@infineon.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | tpm: Add upgrade/reduced mode support for TPM1.2 modules | expand |
On Wed, Jun 01, 2022 at 10:38:11AM +0200, Stefan Mahnke-Hartmann wrote: > In case a TPM in failure mode is detected, the TPM should be accessible > through a transparent communication channel for analysing purposes (e.g. > TPM_GetTestResult) or a field upgrade. Since a TPM in failure mode has > similar reduced functionality as in field upgrade mode, the flag > TPM_CHIP_FLAG_FIRMWARE_UPGRADE_MODE is also valid. > > As described in TCG TPM Main Part1 Design Principles, Revision 116, > chapter 9.2.1. the TPM also allows an update function in case a TPM is > in failure mode. > > If the TPM in failure mode is detected, the function tpm1_auto_startup() > sets TPM_CHIP_FLAG_FIRMWARE_UPGRADE_MODE flag. This patch simply follows > the same rationale as TPM2 in field upgrade mode. "following the rationale" does not give a clue what it does. Also minor nit: write in imperative from, and please do not say "this patch". It won't be a patch, once it is in git. > Signed-off-by: Stefan Mahnke-Hartmann <stefan.mahnke-hartmann@infineon.com> > --- > If you have any better suggestions, please let me know. > > drivers/char/tpm/tpm1-cmd.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/drivers/char/tpm/tpm1-cmd.c b/drivers/char/tpm/tpm1-cmd.c > index f7dc986fa4a0..7a42d74c450c 100644 > --- a/drivers/char/tpm/tpm1-cmd.c > +++ b/drivers/char/tpm/tpm1-cmd.c > @@ -710,8 +710,10 @@ int tpm1_auto_startup(struct tpm_chip *chip) > goto out; > rc = tpm1_do_selftest(chip); > if (rc) { > - dev_err(&chip->dev, "TPM self test failed\n"); > - goto out; > + dev_err(&chip->dev, "TPM self test failed, so the TPM has limited functionality\n"); > + /* A TPM in this state possibly allows or needs a firmware upgrade */ > + chip->flags |= TPM_CHIP_FLAG_FIRMWARE_UPGRADE; > + rc = 0; > } > > return rc; > -- > 2.25.1 > Why all error codes trigger this action, e.g. all possible TPM2 errors and -ETIME? BR, Jarkko
diff --git a/drivers/char/tpm/tpm1-cmd.c b/drivers/char/tpm/tpm1-cmd.c index f7dc986fa4a0..7a42d74c450c 100644 --- a/drivers/char/tpm/tpm1-cmd.c +++ b/drivers/char/tpm/tpm1-cmd.c @@ -710,8 +710,10 @@ int tpm1_auto_startup(struct tpm_chip *chip) goto out; rc = tpm1_do_selftest(chip); if (rc) { - dev_err(&chip->dev, "TPM self test failed\n"); - goto out; + dev_err(&chip->dev, "TPM self test failed, so the TPM has limited functionality\n"); + /* A TPM in this state possibly allows or needs a firmware upgrade */ + chip->flags |= TPM_CHIP_FLAG_FIRMWARE_UPGRADE; + rc = 0; } return rc;
In case a TPM in failure mode is detected, the TPM should be accessible through a transparent communication channel for analysing purposes (e.g. TPM_GetTestResult) or a field upgrade. Since a TPM in failure mode has similar reduced functionality as in field upgrade mode, the flag TPM_CHIP_FLAG_FIRMWARE_UPGRADE_MODE is also valid. As described in TCG TPM Main Part1 Design Principles, Revision 116, chapter 9.2.1. the TPM also allows an update function in case a TPM is in failure mode. If the TPM in failure mode is detected, the function tpm1_auto_startup() sets TPM_CHIP_FLAG_FIRMWARE_UPGRADE_MODE flag. This patch simply follows the same rationale as TPM2 in field upgrade mode. Signed-off-by: Stefan Mahnke-Hartmann <stefan.mahnke-hartmann@infineon.com> --- If you have any better suggestions, please let me know. drivers/char/tpm/tpm1-cmd.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)