1 is a power of two, therefore rounddown_pow_of_two(1) should return 1. It does in case the argument is a variable but in case it's a constant it behaves wrong and returns 0. Probably nobody ever did it so this was never noticed, however net/drivers/vmxnet3 with latest GCC does and breaks on unicpu systems. This is similar to Rolf's patch to roundup_pow_of_two(1). Cc: Rolf Eike Beer <eike-kernel@sf-tec.de> Cc: opensuse-kernel@opensuse.org Reviewed-by: Jesper Juhl <jj@chaosbits.net> Signed-off-by: Andrei Warkentin <andreiw@vmware.com> --- include/linux/log2.h | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/include/linux/log2.h b/include/linux/log2.h index 25b8086..ccda848 100644 --- a/include/linux/log2.h +++ b/include/linux/log2.h @@ -185,7 +185,7 @@ unsigned long __rounddown_pow_of_two(unsigned long n) #define rounddown_pow_of_two(n) \ ( \ __builtin_constant_p(n) ? ( \ - (n == 1) ? 0 : \ + (n == 1) ? 1 : \ (1UL << ilog2(n))) : \ __rounddown_pow_of_two(n) \ ) -- 1.7.4.1 -- To unsubscribe, e-mail: opensuse-kernel+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-kernel+owner@opensuse.org