From: Arnd Bergmann Date: Fri, 2 Nov 2018 15:14:32 +0000 (+0100) Subject: HID: asus: fix build warning wiht CONFIG_ASUS_WMI disabled X-Git-Tag: v4.20-rc2~30^2~1 X-Git-Url: http://git.samba.org/samba.git/?p=sfrench%2Fcifs-2.6.git;a=commitdiff_plain;h=3fc202e81db70bf60beb9296eefd4e48d6304607 HID: asus: fix build warning wiht CONFIG_ASUS_WMI disabled asus_wmi_evaluate_method() is an empty dummy function when CONFIG_ASUS_WMI is disabled, or not reachable from a built-in device driver. This leads to a theoretical evaluation of an uninitialized variable that the compiler complains about, failing to check that the hardcoded return value makes this an unreachable code path: In file included from include/linux/printk.h:336, from include/linux/kernel.h:14, from include/linux/list.h:9, from include/linux/dmi.h:5, from drivers/hid/hid-asus.c:29: drivers/hid/hid-asus.c: In function 'asus_input_configured': include/linux/dynamic_debug.h:135:3: error: 'value' may be used uninitialized in this function [-Werror=maybe-uninitialized] __dynamic_dev_dbg(&descriptor, dev, fmt, \ ^~~~~~~~~~~~~~~~~ drivers/hid/hid-asus.c:359:6: note: 'value' was declared here u32 value; ^~~~~ With an extra IS_ENABLED() check, the warning goes away. Fixes: 3b692c55e58d ("HID: asus: only support backlight when it's not driven by WMI") Signed-off-by: Arnd Bergmann Acked-by: Geert Uytterhoeven Signed-off-by: Jiri Kosina --- diff --git a/drivers/hid/hid-asus.c b/drivers/hid/hid-asus.c index dc6d6477e961..a1fa2fc8c9b5 100644 --- a/drivers/hid/hid-asus.c +++ b/drivers/hid/hid-asus.c @@ -359,6 +359,9 @@ static bool asus_kbd_wmi_led_control_present(struct hid_device *hdev) u32 value; int ret; + if (!IS_ENABLED(CONFIG_ASUS_WMI)) + return false; + ret = asus_wmi_evaluate_method(ASUS_WMI_METHODID_DSTS2, ASUS_WMI_DEVID_KBD_BACKLIGHT, 0, &value); hid_dbg(hdev, "WMI backlight check: rc %d value %x", ret, value);