There are two problems with our current interrupt probing: firstly the
TPM_CHIP_FLAG_IRQ never gets set initially, so a check for interrupts
is never done. Fix this by setting the flag before we generate and
interrupt for probing. Secondly our IRQ setup may be ineffective on a
TPM without legacy access cycles becuase according to the TPM
Interface Specification the interrupt registers are only writeable in
the current locality, so issue a request_locality before setting up
the interrupts.
Signed-off-by: James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx>
---
v2: improved description
---
drivers/char/tpm/tpm_tis_core.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)
diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index 0c07da8cd680..12b657ed3a39 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -809,6 +809,19 @@ static int tpm_tis_probe_irq_single(struct tpm_chip *chip,
}
priv->irq = irq;
+ /*
+ * note writes to the interrupt registers are only effective
+ * when the TPM is in the active locality, so we have to
+ * request the locality here to get the interrupt set up.
+ * This request has no corresponding release, because the
+ * locality will be relinquished at the end of the tpm command
+ * that probes the interrupts
+ */
+ if (request_locality(chip, 0) != 0) {
+ dev_err(&chip->dev, "failed to gain locality for irq probe\n");
+ return -EBUSY;
+ }
+
rc = tpm_tis_read8(priv, TPM_INT_VECTOR(priv->locality),
&original_int_vec);
if (rc < 0)
@@ -836,6 +849,7 @@ static int tpm_tis_probe_irq_single(struct tpm_chip *chip,
return rc;
priv->irq_tested = false;
+ chip->flags |= TPM_CHIP_FLAG_IRQ;
/* Generate an interrupt by having the core call through to
* tpm_tis_send
--
2.28.0
