Re: [PATCH v3 2/2] clk: tests: Add missing test cases for mux determine_rate

[Yang Xiwen]

On 5/3/2023 11:08 AM, Stephen Boyd wrote:
> Quoting Yang Xiwen via B4 Relay (2023-04-26 12:34:17)
>> diff --git a/drivers/clk/clk_test.c b/drivers/clk/clk_test.c
>> index f9a5c2964c65d..4f7f9a964637a 100644
>> --- a/drivers/clk/clk_test.c
>> +++ b/drivers/clk/clk_test.c
>> @@ -2194,7 +2194,47 @@ static void clk_leaf_mux_set_rate_parent_test_exit(struct kunit *test)
>>   * parent, the rate request structure returned by __clk_determine_rate
>>   * is sane and will be what we expect.
>>   */
>> -static void clk_leaf_mux_set_rate_parent_determine_rate(struct kunit *test)
> 
> Just leave this one alone and put the other test cases right after it.
> Don't rename it and also move it lower down. It makes the diff hard to
> read.
> 
>> +static void clk_leaf_mux_set_rate_parent_determine_rate_case1(struct kunit *test)
> 
> Please add a comment above each test case like there is for
> clk_leaf_mux_set_rate_parent_determine_rate() that describes what is
> being tested.
> 
>> +{
>> +       struct clk_leaf_mux_ctx *ctx = test->priv;
>> +       struct clk_hw *hw = &ctx->hw;
>> +       struct clk *clk = clk_hw_get_clk(hw, NULL);
>> +       struct clk_rate_request req;
>> +       unsigned long rate;
>> +       int ret;
>> +
>> +       rate = clk_get_rate(clk);
>> +       KUNIT_ASSERT_EQ(test, rate, DUMMY_CLOCK_RATE_1);
>> +
>> +       clk_hw_init_rate_request(hw, &req, 0);
>> +
>> +       ret = __clk_determine_rate(hw, &req);
>> +       KUNIT_ASSERT_EQ(test, ret, -EINVAL);
>> +
>> +       clk_put(clk);
>> +}
>> +
>> +static void clk_leaf_mux_set_rate_parent_determine_rate_case2(struct kunit *test)
>> +{
>> +       struct clk_leaf_mux_ctx *ctx = test->priv;
>> +       struct clk_hw *hw = &ctx->hw;
>> +       struct clk *clk = clk_hw_get_clk(hw, NULL);
>> +       struct clk_rate_request req;
>> +       unsigned long rate;
>> +       int ret;
>> +
>> +       rate = clk_get_rate(clk);
>> +       KUNIT_ASSERT_EQ(test, rate, DUMMY_CLOCK_RATE_1);
>> +
>> +       clk_hw_init_rate_request(hw, &req, DUMMY_CLOCK_INIT_RATE);
>> +
>> +       ret = __clk_determine_rate(hw, &req);
>> +       KUNIT_ASSERT_EQ(test, ret, -EINVAL);
> 
> There should be some KUNIT_EXPECT statement in each test.>
>> +
>> +       clk_put(clk);
>> +}
>> +
>> +static void clk_leaf_mux_set_rate_parent_determine_rate_case3(struct kunit *test)
>>  {
>>         struct clk_leaf_mux_ctx *ctx = test->priv;
>>         struct clk_hw *hw = &ctx->hw;
>> @@ -2218,8 +2258,95 @@ static void clk_leaf_mux_set_rate_parent_determine_rate(struct kunit *test)
>>         clk_put(clk);
>>  }
>>  
>> +static void clk_leaf_mux_set_rate_parent_determine_rate_case4(struct kunit *test)
>> +{
>> +       struct clk_leaf_mux_ctx *ctx = test->priv;
>> +       struct clk_hw *hw = &ctx->hw;
>> +       struct clk *clk = clk_hw_get_clk(hw, NULL);
>> +       struct clk_rate_request req;
>> +       unsigned long rate;
>> +       int ret;
>> +
>> +       rate = clk_get_rate(clk);
>> +       KUNIT_ASSERT_EQ(test, rate, DUMMY_CLOCK_RATE_1);
>> +
>> +       clk_hw_init_rate_request(hw, &req, (DUMMY_CLOCK_RATE_1 + DUMMY_CLOCK_RATE_2) / 2);
>> +
>> +       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);
>> +}
>> +
>> +static void clk_leaf_mux_set_rate_parent_determine_rate_case5(struct kunit *test)
>> +{
>> +       struct clk_leaf_mux_ctx *ctx = test->priv;
>> +       struct clk_hw *hw = &ctx->hw;
>> +       struct clk *clk = clk_hw_get_clk(hw, NULL);
>> +       struct clk_rate_request req;
>> +       unsigned long rate;
>> +       int ret;
>> +
>> +       rate = clk_get_rate(clk);
>> +       KUNIT_ASSERT_EQ(test, rate, DUMMY_CLOCK_RATE_1);
>> +
>> +       clk_hw_init_rate_request(hw, &req, DUMMY_CLOCK_RATE_2 + 100000);
>> +
>> +       ret = __clk_determine_rate(hw, &req);
>> +       KUNIT_ASSERT_EQ(test, ret, 0);
>> +
>> +       KUNIT_EXPECT_EQ(test, req.rate, DUMMY_CLOCK_RATE_2);
>> +       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);
>> +
>> +       clk_put(clk);
>> +}
>> +
>> +static void clk_leaf_mux_set_rate_parent_determine_rate_case6(struct kunit *test)
>> +{
>> +       struct clk_leaf_mux_ctx *ctx = test->priv;
>> +       struct clk_hw *hw = &ctx->hw;
>> +       struct clk *clk = clk_hw_get_clk(hw, NULL);
>> +       struct clk_rate_request req;
>> +       unsigned long rate;
>> +       int ret;
>> +
>> +       rate = clk_get_rate(clk);
>> +       KUNIT_ASSERT_EQ(test, rate, DUMMY_CLOCK_RATE_1);
>> +
>> +       clk_hw_init_rate_request(hw, &req, ULONG_MAX);
>> +
>> +       ret = __clk_determine_rate(hw, &req);
>> +       KUNIT_ASSERT_EQ(test, ret, 0);
>> +
>> +       KUNIT_EXPECT_EQ(test, req.rate, DUMMY_CLOCK_RATE_2);
>> +       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);
>> +
>> +       clk_put(clk);
>> +}
>> +
>> +/* We test 6 cases here:
>> + * 1. The requested rate is 0;
>> + * 2. The requested rate is not 0 but lower than any rate that parents could offer;
>> + * 3. The requested rate is exactly one of the parents' clock rate;
>> + * 4. The requested rate is between the lowest clock rate and the highest clock rate that the parents could offer;
>> + * 5. The requested rate is larger than all rates that parents could offer;
>> + * 6. The requested rate is ULONG_MAX.
>> + *
>> + * Hopefully they covered all cases.
>> + */
> 
> Please remove this comment and name the cases better.
Thanks, I will follow your suggestions and rename them in next version.
> 
>>  static struct kunit_case clk_leaf_mux_set_rate_parent_test_cases[] = {
>> -       KUNIT_CASE(clk_leaf_mux_set_rate_parent_determine_rate),
>> +       KUNIT_CASE(clk_leaf_mux_set_rate_parent_determine_rate_case1),
> 
> Maybe call it clk_leaf_mux_determine_rate_request_zero?
> 
>> +       KUNIT_CASE(clk_leaf_mux_set_rate_parent_determine_rate_case2),
> 
> clk_leaf_mux_determine_rate_lower_than_parents_fails
> 
>> +       KUNIT_CASE(clk_leaf_mux_set_rate_parent_determine_rate_case3),
> 
> clk_leaf_mux_determine_rate_exactly_parent1
> 
>> +       KUNIT_CASE(clk_leaf_mux_set_rate_parent_determine_rate_case4),
> 
> I'm not sure I understand what is being tested in this case. Are we
> testing that __clk_determine_rate() with a rate between parent0 and
> parent1 picks parent1?Yes, that's it. For example, 2 parents offer 100MHz and 200MHz, we
request 150MHz, and 100MHz should be determined(the highest possible
rate lower than or equal to the requested rate). Actually the flag
CLK_MUX_ROUND_CLOSEST is still missing in the test cases. I suppose it
should be in another patchset.
> 
>> +       KUNIT_CASE(clk_leaf_mux_set_rate_parent_determine_rate_case5),
> 
> clk_leaf_mux_determine_rate_larger_than_parents
> 
>> +       KUNIT_CASE(clk_leaf_mux_set_rate_parent_determine_rate_case6),
> 
> clk_leaf_mux_determine_rate_ULONG_MAX_picks_parent1
-- 
Best regards,
Yang Xiwen