2015-06-10 20:05:21

by Daniel Thompson

Subject: [PATCH] clk: fixed: Add comment to clk_fixed_set_rate

Currently it is not made explicit why clk_fixed_set_rate() can ignore
its arguments and unconditionally return success. Add a comment
to explain this.

We also mark the clk_ops table const since it should never be
modified at runtime.

Suggested-by: Stephen Boyd <[email protected]>
Signed-off-by: Daniel Thompson <[email protected]>
---

Notes:
Changes here emerged from Stephen Boyd's code review of (partiall)
borrowed code. This patch applies his review comments to the
original code.

drivers/clk/clk-fixed-factor.c | 8 +++++++-
include/linux/clk-provider.h | 2 +-
2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/clk/clk-fixed-factor.c b/drivers/clk/clk-fixed-factor.c
index e186db2..fccabe4 100644
--- a/drivers/clk/clk-fixed-factor.c
+++ b/drivers/clk/clk-fixed-factor.c
@@ -55,10 +55,16 @@ static long clk_factor_round_rate(struct clk_hw *hw, unsigned long rate,
static int clk_factor_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
+ /*
+ * We must report success but we can do so unconditionally because
+ * clk_factor_round_rate returns values that ensure this call is a
+ * nop.
+ */
+
return 0;
}

-struct clk_ops clk_fixed_factor_ops = {
+const struct clk_ops clk_fixed_factor_ops = {
.round_rate = clk_factor_round_rate,
.set_rate = clk_factor_set_rate,
.recalc_rate = clk_factor_recalc_rate,
diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index 6d55c31..1af9579 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -459,7 +459,7 @@ struct clk_fixed_factor {
unsigned int div;
};

-extern struct clk_ops clk_fixed_factor_ops;
+extern const struct clk_ops clk_fixed_factor_ops;
struct clk *clk_register_fixed_factor(struct device *dev, const char *name,
const char *parent_name, unsigned long flags,
unsigned int mult, unsigned int div);
--
2.4.2

2015-06-10 21:23:47

by Stephen Boyd

Subject: Re: [PATCH] clk: fixed: Add comment to clk_fixed_set_rate

On 06/10, Daniel Thompson wrote:
> Currently it is not made explicit why clk_fixed_set_rate() can ignore
> its arguments and unconditionally return success. Add a comment
> to explain this.
>
> We also mark the clk_ops table const since it should never be
> modified at runtime.
>
> Suggested-by: Stephen Boyd <[email protected]>
> Signed-off-by: Daniel Thompson <[email protected]>
> ---

Applied to clk-next

--
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