tpm_tis: Ensure interrupts are disabled when the driver starts

This should be done very early, before anything could possibly
cause the TPM to generate an interrupt. If the IRQ line is shared
with another driver causing an interrupt before setting up our
handler will be very bad.

Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Martin Wilck <Martin.Wilck@ts.fujitsu.com>
Tested-by: Scot Doyle <lkml14@scotdoyle.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Acked-by: Peter Huewe <peterhuewe@gmx.de>

drivers/char/tpm/tpm_tis.c

@@ -677,6 +677,15 @@ static int tpm_tis_init(struct device *dev, struct tpm_info *tpm_info,
 		goto out_err;
 	}
 
+	/* Take control of the TPM's interrupt hardware and shut it off */
+	intmask = ioread32(chip->vendor.iobase +
+			   TPM_INT_ENABLE(chip->vendor.locality));
+	intmask |= TPM_INTF_CMD_READY_INT | TPM_INTF_LOCALITY_CHANGE_INT |
+		   TPM_INTF_DATA_AVAIL_INT | TPM_INTF_STS_VALID_INT;
+	intmask &= ~TPM_GLOBAL_INT_ENABLE;
+	iowrite32(intmask,
+		  chip->vendor.iobase + TPM_INT_ENABLE(chip->vendor.locality));
+
 	if (request_locality(chip, 0) != 0) {
 		rc = -ENODEV;
 		goto out_err;
@@ -735,17 +744,6 @@ static int tpm_tis_init(struct device *dev, struct tpm_info *tpm_info,
 	init_waitqueue_head(&chip->vendor.read_queue);
 	init_waitqueue_head(&chip->vendor.int_queue);
 
-	intmask =
-	    ioread32(chip->vendor.iobase +
-		     TPM_INT_ENABLE(chip->vendor.locality));
-
-	intmask |= TPM_INTF_CMD_READY_INT
-	    | TPM_INTF_LOCALITY_CHANGE_INT | TPM_INTF_DATA_AVAIL_INT
-	    | TPM_INTF_STS_VALID_INT;
-
-	iowrite32(intmask,
-		  chip->vendor.iobase +
-		  TPM_INT_ENABLE(chip->vendor.locality));
 	if (interrupts)
 		chip->vendor.irq = tpm_info->irq;
 	if (interrupts && !chip->vendor.irq) {