diff options
Diffstat (limited to 'chip/stm32/clock-stm32h7.c')
| -rw-r--r-- | chip/stm32/clock-stm32h7.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/chip/stm32/clock-stm32h7.c b/chip/stm32/clock-stm32h7.c index a3ebb9aa36..f41a76b87a 100644 --- a/chip/stm32/clock-stm32h7.c +++ b/chip/stm32/clock-stm32h7.c @@ -32,7 +32,13 @@ * with /4 prescaler (2^2): period 125 us, full range ~8s */ #define LPTIM_PRESCALER_LOG2 2 -#define LPTIM_PRESCALER BIT(LPTIM_PRESCALER_LOG2) +/* + * LPTIM_PRESCALER and LPTIM_PERIOD_US have to be signed, because we compare + * them to an int to decide whether to go to deep sleep. Simply using BIT() + * makes them unsigned, which causes a bug in deep sleep behavior. + * TODO(b/140538084): Explain exactly what the bug is. + */ +#define LPTIM_PRESCALER ((int)BIT(LPTIM_PRESCALER_LOG2)) #define LPTIM_PERIOD_US (SECOND / (STM32_LSI_CLOCK / LPTIM_PRESCALER)) /* |