3.2.91-rc1 review patch. If anyone has any objections, please let me know.
------------------
From: Arnd Bergmann <a...@arndb.de>
commit fe8c470ab87d90e4b5115902dd94eced7e3305c3 upstream.
gcc -O2 cannot always prove that the loop in acpi_power_get_inferred_state()
is enterered at least once, so it assumes that cur_state might not get
initialized:
drivers/acpi/power.c: In function 'acpi_power_get_inferred_state':
drivers/acpi/power.c:222:9: error: 'cur_state' may be used uninitialized in
this function [-Werror=maybe-uninitialized]
This sets the variable to zero at the start of the loop, to ensure that
there is well-defined behavior even for an empty list. This gets rid of
the warning.
The warning first showed up when the -Os flag got removed in a bug fix
patch in linux-4.11-rc5.
I would suggest merging this addon patch on top of that bug fix to avoid
introducing a new warning in the stable kernels.
Fixes: 61b79e16c68d (ACPI: Fix incompatibility with mcount-based function graph
tracing)
Signed-off-by: Arnd Bergmann <a...@arndb.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wyso...@intel.com>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <b...@decadent.org.uk>
---
--- a/drivers/acpi/power.c
+++ b/drivers/acpi/power.c
@@ -152,7 +152,7 @@ static int acpi_power_get_list_state(str
return -EINVAL;
/* The state of the list is 'on' IFF all resources are 'on'. */
-
+ cur_state = 0;
for (i = 0; i < list->count; i++) {
struct acpi_power_resource *resource;
acpi_handle handle = list->handles[i];
