tpm/tpm_tis: Free IRQ if probing fails

Call disable_interrupts() if we have to revert to polling in order not to
unnecessarily reserve the IRQ for the life-cycle of the driver.

Cc: stable@vger.kernel.org # 4.5.x
Reported-by: Hans de Goede <hdegoede@redhat.com>
Fixes: e3837e74 ("tpm_tis: Refactor the interrupt setup")
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

drivers/char/tpm/tpm_tis_core.c

@@ -433,6 +433,9 @@ static void disable_interrupts(struct tpm_chip *chip)
 	u32 intmask;
 	int rc;
 
+	if (priv->irq == 0)
+		return;
+
 	rc = tpm_tis_read32(priv, TPM_INT_ENABLE(priv->locality), &intmask);
 	if (rc < 0)
 		intmask = 0;
@@ -1062,9 +1065,12 @@ int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
 		if (irq) {
 			tpm_tis_probe_irq_single(chip, intmask, IRQF_SHARED,
 						 irq);
-			if (!(chip->flags & TPM_CHIP_FLAG_IRQ))
+			if (!(chip->flags & TPM_CHIP_FLAG_IRQ)) {
 				dev_err(&chip->dev, FW_BUG
 					"TPM interrupt not working, polling instead\n");
+
+				disable_interrupts(chip);
+			}
 		} else {
 			tpm_tis_probe_irq(chip, intmask);
 		}