The bind_evtchn_to_irqhandler() function can never return 0. Historically, IRQ functions used to return zero on error, but then we added an architecture where that was a valid IRQ so it went from being an error to being success (but in a limitted way, just enough for that arch to boot, I guess). Eventually we removed it and we will never allow zero to be a valid IRQ again.
The problem here is that if zero were an invalid IRQ then we should return a negative error code but the code returns zero/success. Change the code to check for negative error codes so it's not question of how the zero should be handled. Signed-off-by: Dan Carpenter <[email protected]> --- >From static analysis. Untested. drivers/char/tpm/xen-tpmfront.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/char/tpm/xen-tpmfront.c b/drivers/char/tpm/xen-tpmfront.c index 3c0cce57c4ae..731444eac5f2 100644 --- a/drivers/char/tpm/xen-tpmfront.c +++ b/drivers/char/tpm/xen-tpmfront.c @@ -266,7 +266,7 @@ static int setup_ring(struct xenbus_device *dev, struct tpm_private *priv) rv = bind_evtchn_to_irqhandler(priv->evtchn, tpmif_interrupt, 0, "tpmif", priv); - if (rv <= 0) { + if (rv < 0) { xenbus_dev_fatal(dev, rv, "allocating TPM irq"); return rv; } -- 2.53.0
