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authorDavid Gibson <david@gibson.dropbear.id.au>2020-06-19 13:30:40 +1000
committerJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>2020-07-02 17:49:00 +0300
commit72d0556dca39f45eca6c4c085e9eb0fc70aec025 (patch)
tree5c30412edcf314d164e4d35f8fb30d8b026d254e /drivers/char
parent82efeb161c090072ab493ab8c8f8a551727f586e (diff)
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.c14
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 {