[PATCH] tpm_tis: Verify ACPI-specified interrupt

[Scot Doyle <lkml14@scotdoyle.com>]

Some machines, such as the Acer C720 and Toshiba CB35, have TPMs
that do not use interrupts while also having an ACPI TPM entry
indicating a specific interrupt to be used. Since this interrupt
is invalid, these machines freeze on resume until the interrupt
times out.

Generate the ACPI-specified interrupt. If none is received, then
fall back to polling mode.

Signed-off-by: Scot Doyle <lkml14@scotdoyle.com>
Tested-by: James Duley <jagduley@gmail.com>
Tested-by: Michael Mullin <masmullin@gmail.com>
---
  drivers/char/tpm/tpm_tis.c | 14 ++++++++------
  1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/char/tpm/tpm_tis.c b/drivers/char/tpm/tpm_tis.c
index 2c46734..736ed4a 100644
--- a/drivers/char/tpm/tpm_tis.c
+++ b/drivers/char/tpm/tpm_tis.c
@@ -633,12 +633,14 @@ static int tpm_tis_init(struct device *dev, resource_size_t start,
  	iowrite32(intmask,
  		  chip->vendor.iobase +
  		  TPM_INT_ENABLE(chip->vendor.locality));
-	if (interrupts)
-		chip->vendor.irq = irq;
-	if (interrupts && !chip->vendor.irq) {
-		irq_s =
-		    ioread8(chip->vendor.iobase +
-			    TPM_INT_VECTOR(chip->vendor.locality));
+	chip->vendor.irq = 0;
+	if (interrupts) {
+		if (irq)
+			irq_s = irq;
+		else
+			irq_s =
+			    ioread8(chip->vendor.iobase +
+				    TPM_INT_VECTOR(chip->vendor.locality));
  		if (irq_s) {
  			irq_e = irq_s;
  		} else {
-- 
2.0.4