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authorArnd Bergmann <arnd@arndb.de>2017-03-01 12:15:29 +0300
committerGuenter Roeck <linux@roeck-us.net>2017-03-01 17:15:10 +0300
commit3736d4eb6af37492aeded7fec0072dedd959c842 (patch)
tree20d8d96e44e8af895e3dee3003db3d0ba10c1088
parent8d5755b3f77b57447ce5de253ef704ad028474d3 (diff)
downloadlinux-3736d4eb6af37492aeded7fec0072dedd959c842.tar.xz
watchdog: kempld: fix gcc-4.3 build
gcc-4.3 can't decide whether the constant value in kempld_prescaler[PRESCALER_21] is built-time constant or not, and gets confused by the logic in do_div(): drivers/watchdog/kempld_wdt.o: In function `kempld_wdt_set_stage_timeout': kempld_wdt.c:(.text.kempld_wdt_set_stage_timeout+0x130): undefined reference to `__aeabi_uldivmod' This adds a call to ACCESS_ONCE() to force it to not consider it to be constant, and leaves the more efficient normal case in place for modern compilers, using an #ifdef to annotate why we do this hack. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
-rw-r--r--drivers/watchdog/kempld_wdt.c9
1 files changed, 8 insertions, 1 deletions
diff --git a/drivers/watchdog/kempld_wdt.c b/drivers/watchdog/kempld_wdt.c
index 73c46b3a09ab..2f3b049ea301 100644
--- a/drivers/watchdog/kempld_wdt.c
+++ b/drivers/watchdog/kempld_wdt.c
@@ -140,12 +140,19 @@ static int kempld_wdt_set_stage_timeout(struct kempld_wdt_data *wdt_data,
unsigned int timeout)
{
struct kempld_device_data *pld = wdt_data->pld;
- u32 prescaler = kempld_prescaler[PRESCALER_21];
+ u32 prescaler;
u64 stage_timeout64;
u32 stage_timeout;
u32 remainder;
u8 stage_cfg;
+#if GCC_VERSION < 40400
+ /* work around a bug compiling do_div() */
+ prescaler = READ_ONCE(kempld_prescaler[PRESCALER_21]);
+#else
+ prescaler = kempld_prescaler[PRESCALER_21];
+#endif
+
if (!stage)
return -EINVAL;