[PATCH v2 2/2] clk: fractional-divider: fix sparse warnings

From: Andy Shevchenko
Date: Mon Mar 30 2015 - 14:58:44 EST


Sparse complains about possible imbalance in locking.

drivers/clk/clk-fractional-divider.c:37:9: warning: context imbalance in 'clk_fd_recalc_rate' - different lock contexts for basic block
drivers/clk/clk-fractional-divider.c:61:12: warning: context imbalance in 'clk_fd_set_rate' - different lock contexts for basic block

Let's rewrite code to fix this and make it more straight.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
drivers/clk/clk-fractional-divider.c | 35 +++++++++++++++++++++--------------
1 file changed, 21 insertions(+), 14 deletions(-)

diff --git a/drivers/clk/clk-fractional-divider.c b/drivers/clk/clk-fractional-divider.c
index 9c53704..3766da8 100644
--- a/drivers/clk/clk-fractional-divider.c
+++ b/drivers/clk/clk-fractional-divider.c
@@ -26,13 +26,13 @@ static unsigned long clk_fd_recalc_rate(struct clk_hw *hw,
unsigned long flags = 0;
u32 val;

- if (fd->lock)
+ if (fd->lock) {
spin_lock_irqsave(fd->lock, flags);
-
- val = clk_readl(fd->reg);
-
- if (fd->lock)
+ val = clk_readl(fd->reg);
spin_unlock_irqrestore(fd->lock, flags);
+ } else {
+ val = clk_readl(fd->reg);
+ }

m = (val & fd->mmask) >> fd->mshift;
n = (val & fd->nmask) >> fd->nshift;
@@ -58,27 +58,34 @@ static long clk_fd_round_rate(struct clk_hw *hw, unsigned long rate,
return mult_frac(rate, m, n);
}

+static void clk_fd_update(struct clk_fractional_divider *fd,
+ unsigned long m, unsigned long n)
+{
+ u32 val;
+
+ val = clk_readl(fd->reg);
+ val &= ~(fd->mmask | fd->nmask);
+ val |= (m << fd->mshift) | (n << fd->nshift);
+ clk_writel(val, fd->reg);
+}
+
static int clk_fd_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct clk_fractional_divider *fd = to_clk_fd(hw);
unsigned long flags = 0;
unsigned long n, m;
- u32 val;

rational_best_approximation(rate, parent_rate,
fd->mmask >> fd->mshift, fd->nmask >> fd->nshift, &m, &n);

- if (fd->lock)
+ if (fd->lock) {
spin_lock_irqsave(fd->lock, flags);
-
- val = clk_readl(fd->reg);
- val &= ~(fd->mmask | fd->nmask);
- val |= (m << fd->mshift) | (n << fd->nshift);
- clk_writel(val, fd->reg);
-
- if (fd->lock)
+ clk_fd_update(fd, m, n);
spin_unlock_irqrestore(fd->lock, flags);
+ } else {
+ clk_fd_update(fd, m, n);
+ }

return 0;
}
--
2.1.4

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