Signed-off-by: Yang Xiwen <[email protected]>
---
Changes in v2:
- Add a unit test to clk_test.c
- Link to v1: https://lore.kernel.org/r/[email protected]
---
Yang Xiwen (2):
clk: use ULONG_MAX as the initial value for the iteration in clk_mux_determine_rate_flags()
clk: tests: Add missing test case for mux determine_rate
drivers/clk/clk.c | 5 ++++-
drivers/clk/clk_test.c | 9 +++++++++
2 files changed, 13 insertions(+), 1 deletion(-)
---
base-commit: 76f598ba7d8e2bfb4855b5298caedd5af0c374a8
change-id: 20230421-clk-64c6b6e21cdb
Best regards,
--
Yang Xiwen <[email protected]>
From: Yang Xiwen <[email protected]>
Add a missing test case for determine_rate implemented by mux. It tests
the behavior of determine_rate when requesting a rate that none of the
parents could give.
Signed-off-by: Yang Xiwen <[email protected]>
---
drivers/clk/clk_test.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/drivers/clk/clk_test.c b/drivers/clk/clk_test.c
index f9a5c2964c65d..9b1c90de90454 100644
--- a/drivers/clk/clk_test.c
+++ b/drivers/clk/clk_test.c
@@ -2215,6 +2215,15 @@ static void clk_leaf_mux_set_rate_parent_determine_rate(struct kunit *test)
KUNIT_EXPECT_EQ(test, req.best_parent_rate, DUMMY_CLOCK_RATE_2);
KUNIT_EXPECT_PTR_EQ(test, req.best_parent_hw, &ctx->mux_ctx.hw);
+ // Test a non-existant rate which none of the parents could give
+ clk_hw_init_rate_request(hw, &req, DUMMY_CLOCK_INIT_RATE);
+
+ ret = __clk_determine_rate(hw, &req);
+ KUNIT_ASSERT_EQ(test, ret, 0);
+
+ KUNIT_EXPECT_EQ(test, req.rate, DUMMY_CLOCK_RATE_1);
+ KUNIT_EXPECT_EQ(test, req.best_parent_rate, DUMMY_CLOCK_RATE_1);
+ KUNIT_EXPECT_PTR_EQ(test, req.best_parent_hw, &ctx->mux_ctx.hw);
clk_put(clk);
}
--
2.39.2
From: Yang Xiwen <[email protected]>
Currently, clk_mux_determine_rate_flags() use 0 as the initial value for
selecting the best matching parent. However, this will choose a
non-existant rate(0) if the requested rate is closer to 0 than the
minimum rate the parents have.
Fix that by initializing the initial value to ULONG_MAX and treat it as a
magic number.
Signed-off-by: Yang Xiwen <[email protected]>
---
drivers/clk/clk.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index ae07685c7588b..ab8a2acfac8f3 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -541,6 +541,9 @@ EXPORT_SYMBOL_GPL(__clk_is_enabled);
static bool mux_is_better_rate(unsigned long rate, unsigned long now,
unsigned long best, unsigned long flags)
{
+ if (best == ULONG_MAX)
+ return true;
+
if (flags & CLK_MUX_ROUND_CLOSEST)
return abs(now - rate) < abs(best - rate);
@@ -600,7 +603,7 @@ int clk_mux_determine_rate_flags(struct clk_hw *hw,
{
struct clk_core *core = hw->core, *parent, *best_parent = NULL;
int i, num_parents, ret;
- unsigned long best = 0;
+ unsigned long best = ULONG_MAX;
/* if NO_REPARENT flag set, pass through to current parent */
if (core->flags & CLK_SET_RATE_NO_REPARENT) {
--
2.39.2
Quoting Yang Xiwen via B4 Relay (2023-04-25 00:46:40)
> From: Yang Xiwen <[email protected]>
>
> Add a missing test case for determine_rate implemented by mux. It tests
> the behavior of determine_rate when requesting a rate that none of the
> parents could give.
>
> Signed-off-by: Yang Xiwen <[email protected]>
> ---
> drivers/clk/clk_test.c | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
> diff --git a/drivers/clk/clk_test.c b/drivers/clk/clk_test.c
> index f9a5c2964c65d..9b1c90de90454 100644
> --- a/drivers/clk/clk_test.c
> +++ b/drivers/clk/clk_test.c
> @@ -2215,6 +2215,15 @@ static void clk_leaf_mux_set_rate_parent_determine_rate(struct kunit *test)
> KUNIT_EXPECT_EQ(test, req.best_parent_rate, DUMMY_CLOCK_RATE_2);
> KUNIT_EXPECT_PTR_EQ(test, req.best_parent_hw, &ctx->mux_ctx.hw);
>
> + // Test a non-existant rate which none of the parents could give
> + clk_hw_init_rate_request(hw, &req, DUMMY_CLOCK_INIT_RATE);
> +
> + ret = __clk_determine_rate(hw, &req);
> + KUNIT_ASSERT_EQ(test, ret, 0);
> +
> + KUNIT_EXPECT_EQ(test, req.rate, DUMMY_CLOCK_RATE_1);
> + KUNIT_EXPECT_EQ(test, req.best_parent_rate, DUMMY_CLOCK_RATE_1);
> + KUNIT_EXPECT_PTR_EQ(test, req.best_parent_hw, &ctx->mux_ctx.hw);
Please make an entire test case instead of modifying an existing test
case.