On Thursday 01 October 2015 21:17:45 Richard Cochran wrote:
On Wed, Sep 30, 2015 at 01:26:33PM +0200, Arnd Bergmann wrote:
diff --git a/drivers/net/ethernet/intel/igb/igb_ptp.c b/drivers/net/ethernet/intel/igb/igb_ptp.c index 5982f28d521a..c44df87c38de 100644 --- a/drivers/net/ethernet/intel/igb/igb_ptp.c +++ b/drivers/net/ethernet/intel/igb/igb_ptp.c @@ -143,7 +143,7 @@ static void igb_ptp_write_i210(struct igb_adapter *adapter, * sub-nanosecond resolution. */ wr32(E1000_SYSTIML, ts->tv_nsec);
wr32(E1000_SYSTIMH, ts->tv_sec);
wr32(E1000_SYSTIMH, (u32)ts->tv_sec);This cast is unnecessary, because wr32 is writel, and that parameter is a u32.
I tried to use this pattern whenever I convert the 64-bit 'long long' tv_sec member of 'struct timespec64' into a 32-bit number, to annotate the loss of range.
I have thought about defining separate helpers like this
/* result will overflow in 2038 for real time */ static inline s32 time64_to_s32_y2038(time64_t time) { return time; }
/* result will overflow in 2106 for real time */ static inline u32 time64_to_u32_y2106(time64_t time) { return time; }
/* monotonic times can safely be represented as 32 bit */ static inline s32 time64_to_s32_monotonic(time64_t time) { return time; }
This would make it even more explicit, but my fear was that I was adding too much complexity like that.
Arnd