----- David Miller <davem@xxxxxxxxxxxxx> 写道： > From: Chen Gang <gang.chen.5i5j@xxxxxxxxx> > Date: Wed, 21 May 2014 08:19:34 +0800 > > > 'dccp_timestamp_seed' is initialized once by ktime_get_real() in > > dccp_timestamping_init(). It is always less than ktime_get_real() > > in dccp_timestamp(). > > > > Then, ktime_us_delta() in dccp_timestamp() will always return positive > > number. So can use manual type cast to let compiler and do_div() know > > about it to avoid warning. > > > > The related warning (with allmodconfig under unicore32): > > > > CC [M] net/dccp/timer.o > > net/dccp/timer.c: In function ‘dccp_timestamp’: > > net/dccp/timer.c:285: warning: comparison of distinct pointer types lacks a cast > > > > > > Signed-off-by: Chen Gang <gang.chen.5i5j@xxxxxxxxx> > > Applied to net-next, thanks. > > But that type check in include/asm-generic/div64.h is bogus, it should > be checking sizeof(X) == 8 rather than the type thing, it just wants to > make sure that the value is 64-bit regardless of it's signedness. > > The arch local implementations do not do this, and that's why very few > other people notice this warning. Arch-dependent codes implement it with unsigned long long type. And, every warning should not be ignored. -- To unsubscribe from this list: send the line "unsubscribe dccp" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
