[PATCH 3.16 115/148] ALSA: cs4236: fix error return comparison of an unsigned integer

Ben Hutchings
2020-02-08T18:33:53Z

From: Colin Ian King <colin.king@canonical.com>

commit d60229d84846a8399257006af9c5444599f64361 upstream.

The return from pnp_irq is an unsigned integer type resource_size_t
and hence the error check for a positive non-error code is always
going to be true. A check for a non-failure return from pnp_irq
should in fact be for (resource_size_t)-1 rather than >= 0.

Addresses-Coverity: ("Unsigned compared against 0")
Fixes: a9824c868a2c ("[ALSA] Add CS4232 PnP BIOS support")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20191122131354.58042-1-colin.king@canonical.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
sound/isa/cs423x/cs4236.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/sound/isa/cs423x/cs4236.c
+++ b/sound/isa/cs423x/cs4236.c
@@ -293,7 +293,8 @@ static int snd_cs423x_pnp_init_mpu(int d
} else {
mpu_port[dev] = pnp_port_start(pdev, 0);
if (mpu_irq[dev] >= 0 &&
- pnp_irq_valid(pdev, 0) && pnp_irq(pdev, 0) >= 0) {
+ pnp_irq_valid(pdev, 0) &&
+ pnp_irq(pdev, 0) != (resource_size_t)-1) {
mpu_irq[dev] = pnp_irq(pdev, 0);
} else {
mpu_irq[dev] = -1; /* disable interrupt */