| Message ID | 20181102151443.758229-1-arnd@arndb.de (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Jiri Kosina |
| Headers | show |
| Series | HID: asus: fix build warning wiht CONFIG_ASUS_WMI disabled | expand |
On Fri, Nov 2, 2018 at 4:16 PM Arnd Bergmann <arnd@arndb.de> wrote: > 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 <arnd@arndb.de> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Gr{oetje,eeting}s, Geert
On Fri, 2 Nov 2018, Arnd Bergmann wrote: > 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 <arnd@arndb.de> Applied to for-4.20/upstream-fixes. Thanks,
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);
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 <arnd@arndb.de> --- drivers/hid/hid-asus.c | 3 +++ 1 file changed, 3 insertions(+)