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| author | David Gibson <david@gibson.dropbear.id.au> | 2020-06-19 06:30:40 +0300 |
|---|---|---|
| committer | Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> | 2020-07-02 17:49:00 +0300 |
| commit | 72d0556dca39f45eca6c4c085e9eb0fc70aec025 (patch) | |
| tree | 5c30412edcf314d164e4d35f8fb30d8b026d254e /drivers/char | |
| parent | 82efeb161c090072ab493ab8c8f8a551727f586e (diff) | |
| download | linux-72d0556dca39f45eca6c4c085e9eb0fc70aec025.tar.xz | |
tpm: ibmvtpm: Wait for ready buffer before probing for TPM2 attributes
The tpm2_get_cc_attrs_tbl() call will result in TPM commands being issued,
which will need the use of the internal command/response buffer. But,
we're issuing this *before* we've waited to make sure that buffer is
allocated.
This can result in intermittent failures to probe if the hypervisor / TPM
implementation doesn't respond quickly enough. I find it fails almost
every time with an 8 vcpu guest under KVM with software emulated TPM.
To fix it, just move the tpm2_get_cc_attrs_tlb() call after the
existing code to wait for initialization, which will ensure the buffer
is allocated.
Fixes: 18b3670d79ae9 ("tpm: ibmvtpm: Add support for TPM2")
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Diffstat (limited to 'drivers/char')
| -rw-r--r-- | drivers/char/tpm/tpm_ibmvtpm.c | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/drivers/char/tpm/tpm_ibmvtpm.c b/drivers/char/tpm/tpm_ibmvtpm.c index 09fe45246b8c..994385bf37c0 100644 --- a/drivers/char/tpm/tpm_ibmvtpm.c +++ b/drivers/char/tpm/tpm_ibmvtpm.c @@ -683,13 +683,6 @@ static int tpm_ibmvtpm_probe(struct vio_dev *vio_dev, if (rc) goto init_irq_cleanup; - if (!strcmp(id->compat, "IBM,vtpm20")) { - chip->flags |= TPM_CHIP_FLAG_TPM2; - rc = tpm2_get_cc_attrs_tbl(chip); - if (rc) - goto init_irq_cleanup; - } - if (!wait_event_timeout(ibmvtpm->crq_queue.wq, ibmvtpm->rtce_buf != NULL, HZ)) { @@ -697,6 +690,13 @@ static int tpm_ibmvtpm_probe(struct vio_dev *vio_dev, goto init_irq_cleanup; } + if (!strcmp(id->compat, "IBM,vtpm20")) { + chip->flags |= TPM_CHIP_FLAG_TPM2; + rc = tpm2_get_cc_attrs_tbl(chip); + if (rc) + goto init_irq_cleanup; + } + return tpm_chip_register(chip); init_irq_cleanup: do { |