UNSUPPORTED_CMD was previously 0x80000000 (int), but commit 819cddae7cfa
("platform/x86: fujitsu-laptop: Clean up constants") changed it into an
unsigned long due to BIT() being used to define it. As call_fext_func()
returns an int, 0x80000000 would get type promoted when compared to an
unsigned long, which on a 64-bit system would cause it to become
0xffffffff80000000 due to sign extension. This causes one logical
condition in fujitsu-laptop to always be true and another one to always
be false on 64-bit systems. Fix this by reverting UNSUPPORTED_CMD back
to an int.
This patch fixes the following smatch warnings:
drivers/platform/x86/fujitsu-laptop.c:763 acpi_fujitsu_laptop_leds_register() warn: always true condition '(call_fext_func(device, ((1 << (12)) | (1 << (0))), 2, (1 << (16)), 0) != (1 << (31))) => (s32min-s32max != 2147483648)'
drivers/platform/x86/fujitsu-laptop.c:816 acpi_fujitsu_laptop_add() warn: impossible condition '(priv->flags_supported == (1 << (31))) => (0-2147483647,18446744071562067968-u64max == 2147483648)'
Fixes: 819cddae7cfa ("platform/x86: fujitsu-laptop: Clean up constants")
Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Michał Kępień <kernel@xxxxxxxxxx>
---
This fixes a bug introduced by a commit queued for 4.17, so it needs to
be applied on top of for-next.
drivers/platform/x86/fujitsu-laptop.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/platform/x86/fujitsu-laptop.c b/drivers/platform/x86/fujitsu-laptop.c
index 13bcdfea5349..6f4a55a53ced 100644
--- a/drivers/platform/x86/fujitsu-laptop.c
+++ b/drivers/platform/x86/fujitsu-laptop.c
@@ -85,7 +85,7 @@
#define FUNC_BACKLIGHT (BIT(12) | BIT(2))
/* FUNC interface - responses */
-#define UNSUPPORTED_CMD BIT(31)
+#define UNSUPPORTED_CMD 0x80000000
/* FUNC interface - status flags */
#define FLAG_RFKILL BIT(5)
--
2.16.2
