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SubjectRe: [PATCH] clk: add strict of_clk_init dependency check
On 05/02/2014 16:05, Gregory CLEMENT wrote:
> On 05/02/2014 15:48, Gregory CLEMENT wrote:
>> Hi Boris,
>>
>> On 05/02/2014 10:48, Boris BREZILLON wrote:
>>> The parent dependency check is only available on the first parent of a given
>>> clk.
>>>
>>> Add support for strict dependency check: all parents of a given clk must be
>>> initialized.
>>>
>>> Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
>>> ---
>>>
>>> Hello Gregory,
>>>
>>> This patch adds support for strict check on clk dependencies (check if all
>>> parents specified by an DT clk node are initialized).
>>>
>>> I'm not sure this is what you were expecting (maybe testing the first parent
>>> is what you really want), so please feel free to tell me if I'm wrong.
>>>
>>> Best Regards,
>>>
>>> Boris
>>>
>>> drivers/clk/clk.c | 27 +++++++++++++++++++++------
>>> 1 file changed, 21 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
>>> index beb0f8b..6849769 100644
>>> --- a/drivers/clk/clk.c
>>> +++ b/drivers/clk/clk.c
>>> @@ -2543,22 +2543,37 @@ static int parent_ready(struct device_node *np)
>>> {
>>> struct of_phandle_args clkspec;
>>> struct of_clk_provider *provider;
>>> + int num_parents;
>>> + bool found;
>>> + int i;
>>>
>>> /*
>>> * If there is no clock parent, no need to wait for them, then
>>> * we can consider their absence as being ready
>>> */
>>> - if (of_parse_phandle_with_args(np, "clocks", "#clock-cells", 0,
>>> - &clkspec))
>>> + num_parents = of_count_phandle_with_args(np, "clocks", "#clock-cells");
>>> + if (num_parents <= 0)
>>> return 1;
>>>
>>> - /* Check if we have such a provider in our array */
>>> - list_for_each_entry(provider, &of_clk_providers, link) {
>>> - if (provider->node == clkspec.np)
>>> + for (i = 0; i < num_parents; i++) {
>>> + if (of_parse_phandle_with_args(np, "clocks", "#clock-cells", i,
>>> + &clkspec))
>>> return 1;
>>> +
>>> + /* Check if we have such a provider in our array */
>>> + found = false;
>>> + list_for_each_entry(provider, &of_clk_providers, link) {
>>> + if (provider->node == clkspec.np) {
>>> + found = true;
>>> + break;
>> Hum this means that as soon as you have one parent then you consider it
>> as ready. It is better of what I have done because I only test the 1st
>> parent. However I wondered if we should go further by ensuring all the
>> parents are ready.
> My bad, I read the code too fast. Your code already checks that all the
> parents are ready.
>
> So if you agree I will merge your code with mine and send a new patch.

That's fine by me.
>
>> If I am right, there is more than one parent only for the muxer. In this
>> case is it really expected that all the parent are ready?
>>
>> Thanks,
>>
>> Gregory
>>
>>> + }
>>> + }
>>> +
>>> + if (!found)
>>> + return 0;
>>> }
>>>
>>> - return 0;
>>> + return 1;
>>> }
>>>
>>> /**
>>>
>>
>



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