[U-Boot] [PATCH V2 1/2] pci: Support parsing PCI controller DT subnodes

[Marek Vasut]

On 09/01/2018 11:50 PM, Simon Glass wrote:
> Hi Marek,
> 
> On 30 August 2018 at 07:42, Marek Vasut <marek.vasut at gmail.com> wrote:
>> On 08/30/2018 03:32 PM, Bin Meng wrote:
>>> Hi Marek,
>>>
>>> On Thu, Aug 30, 2018 at 1:07 AM Marek Vasut <marek.vasut at gmail.com> wrote:
>>>>
>>>> On 08/29/2018 05:15 PM, Bin Meng wrote:
>>>>> +Simon
>>>>>
>>>>> Hi Marek,
>>>>>
>>>>> On Wed, Aug 29, 2018 at 10:22 PM Marek Vasut <marek.vasut at gmail.com> wrote:
>>>>>>
>>>>>> On 08/24/2018 08:27 PM, Marek Vasut wrote:
>>>>>>> The PCI controller can have DT subnodes describing extra properties
>>>>>>> of particular PCI devices, ie. a PHY attached to an EHCI controller
>>>>>>> on a PCI bus. This patch parses those DT subnodes and assigns a node
>>>>>>> to the PCI device instance, so that the driver can extract details
>>>>>>> from that node and ie. configure the PHY using the PHY subsystem.
>>>>>>>
>>>>>>> Signed-off-by: Marek Vasut <marek.vasut+renesas at gmail.com>
>>>>>>> Cc: Simon Glass <sjg at chromium.org>
>>>>>>> Cc: Tom Rini <trini at konsulko.com>
>>>>>>
>>>>>> Well, bump ?
>>>>>>
>>>>>> This is the only missing patch to get my hardware working properly.
>>>>>
>>>>> I don't think we ever had an agreement on the v1 patch. Simon had a
>>>>> long email that pointed out what Linux does seems like a 'fallback' to
>>>>> find a node with no compatible string.
>>>>>
>>>>> Back to this, if we have to go with this way, please create a test
>>>>> case to cover this scenario.
>>>>
>>>> The fact that it works on a particular board is not tested enough?
>>>> Do we need a custom, special, synthetic test ?
>>>>
>>>
>>> I believe that's always been the requirement against the DM code
>>> changes. I was requested in the past when I changed something in the
>>> DM and I see other people were asked to do so. Like Alex said, it does
>>> not mean this patch was not tested enough, but to ensure future
>>> commits won't break this.
>>
>> So, do you have any suggestion how to implement this test ? It seems
>> Alex posed the same question. It doesn't seem to be trivial in the
>> context of sandbox.
> 
> I suppose you need a PCI_DEVICE() declaration for sandbox, with an
> associated DT node and no compatible string. Then check that you can
> locate the device and that it read a DT property correctly.

Is there any example of this stuff already ?

>>>> Anyway, any feedback on the patch ? Did you test it ? I again only see
>>>> "do this random stuff and that random stuff" , but zero actual feedback.
>>>>
>>>
>>> If "this and that random stuff" means test case I asked for, please
>>> check my proposal on the v1 patch thread which indicated that a proper
>>> test case should be created. You seems to have missed that.
>>
>> So, any feedback on this actual patch ?
> 
> What is 'potention'?

potential typo .

> Is there any check needed that it does not attach the same DT node to
> two different devices? Or perhaps that cannot happen, since we
> shouldn't expect two nodes to share a BDF?

I guess it could happen and I didn't find a good solution to this even
in Linux. The current take on this possibility seems to be "let's live
with it".

> I think it looks OK, assuming this is the way we want to go.
> 
> Regards,
> Simon
> 


-- 
Best regards,
Marek Vasut