From: David Gibson david@gibson.dropbear.id.au
[ Upstream commit 72d0556dca39f45eca6c4c085e9eb0fc70aec025 ]
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 Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/char/tpm/tpm_ibmvtpm.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-)
diff --git a/drivers/char/tpm/tpm_ibmvtpm.c b/drivers/char/tpm/tpm_ibmvtpm.c index 09fe45246b8cc..994385bf37c0c 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 {