From mboxrd@z Thu Jan 1 00:00:00 1970 From: james.hogan@imgtec.com (James Hogan) Date: Tue, 15 Jan 2013 10:28:05 +0000 Subject: [PATCH 1/1] clk-divider: fix is_power_of_two() Message-ID: <1358245685-4392-1-git-send-email-james.hogan@imgtec.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org The macro is_power_of_two() in clk-divider.c was defined as !(i & ~i) which is always true. Correct it to !(i & (i - 1)). Also add brackets around the macro arguments in div_mask and is_power_of_two, as well as around the is_power_of_two expression as a whole to avoid any future operator precedence problems. Signed-off-by: James Hogan Cc: Mike Turquette --- I haven't tested this other than with a couple of compile time asserts. drivers/clk/clk-divider.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/clk/clk-divider.c b/drivers/clk/clk-divider.c index a9204c6..13bca0c 100644 --- a/drivers/clk/clk-divider.c +++ b/drivers/clk/clk-divider.c @@ -29,8 +29,8 @@ #define to_clk_divider(_hw) container_of(_hw, struct clk_divider, hw) -#define div_mask(d) ((1 << (d->width)) - 1) -#define is_power_of_two(i) !(i & ~i) +#define div_mask(d) ((1 << ((d)->width)) - 1) +#define is_power_of_two(i) (!((i) & ((i) - 1))) static unsigned int _get_table_maxdiv(const struct clk_div_table *table) { -- 1.7.7.6