[PATCH] clk: Dont return error when assigned-clocks is empty or missing

[Michal Simek]

On 8/25/23 16:39, Tom Rini wrote:
> On Fri, Aug 25, 2023 at 09:15:09AM +0200, Michal Simek wrote:
>> Hi Tom,
>>
>> On 7/11/23 11:51, Ashok Reddy Soma wrote:
>>> There is a chance that assigned-clock-rates is given and assigned-clocks
>>> could be empty. Dont return error in that case, because the probe of the
>>> corresponding driver will not be called at all if this fails.
>>> Better to continue to look for it and return 0.
>>>
>>> Signed-off-by: Ashok Reddy Soma <ashok.reddy.soma at amd.com>
>>> ---
>>>
>>>    drivers/clk/clk-uclass.c | 8 +++++++-
>>>    1 file changed, 7 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/clk/clk-uclass.c b/drivers/clk/clk-uclass.c
>>> index dc3e9d6a26..f186fcbcdb 100644
>>> --- a/drivers/clk/clk-uclass.c
>>> +++ b/drivers/clk/clk-uclass.c
>>> @@ -329,7 +329,13 @@ static int clk_set_default_rates(struct udevice *dev,
>>>    			dev_dbg(dev,
>>>    				"could not get assigned clock %d (err = %d)\n",
>>>    				index, ret);
>>> -			continue;
>>> +			/* Skip if it is empty */
>>> +			if (ret == -ENOENT) {
>>> +				ret = 0;
>>> +				continue;
>>> +			}
>>> +
>>> +			return ret;
>>>    		}
>>>    		/* This is clk provider device trying to program itself
>>
>> What's your take on this one?  I didn't get reply from Sean.
> 
> I guess, what's the validated upstream dts where this is the case?
> 

It was found by incorrect DT. It means I don't think there is any DT which 
contains this issue.
But that being said we can extend current clock tests to cover this case.
Please look below.

Thanks,
Michal

diff --git a/arch/sandbox/dts/test.dts b/arch/sandbox/dts/test.dts
index ff9f9222e6f9..0f9bedc0065c 100644
--- a/arch/sandbox/dts/test.dts
+++ b/arch/sandbox/dts/test.dts
@@ -589,6 +589,16 @@
                 clock-names = "fixed", "i2c", "spi", "uart2", "uart1";
         };

+       clk-test2 {
+               compatible = "sandbox,clk-test";
+               assigned-clock-rates = <321>;
+       };
+
+       clk-test3 {
+               compatible = "sandbox,clk-test";
+               assigned-clocks = <&clk_sandbox 1>;
+       };
+
         ccf: clk-ccf {
                 compatible = "sandbox,clk-ccf";
         };
diff --git a/test/dm/clk.c b/test/dm/clk.c
index f48de05436bf..71ae32eaff50 100644
--- a/test/dm/clk.c
+++ b/test/dm/clk.c
@@ -36,6 +36,12 @@ static int dm_test_clk_base(struct unit_test_state *uts)
         ut_asserteq(clk_is_match(&clk_method1, &clk_method2), true);
         ut_asserteq(clk_method1.id, clk_method2.id);

+       ut_assertok(uclass_get_device_by_name(UCLASS_MISC, "clk-test2", &dev));
+       ut_assertok(clk_set_defaults(dev, CLK_DEFAULTS_PRE));
+
+       ut_assertok(uclass_get_device_by_name(UCLASS_MISC, "clk-test3", &dev));
+       ut_assertok(clk_set_defaults(dev, CLK_DEFAULTS_PRE));
+
         return 0;
  }