[PATCH 10/14] tegra: usb: Add support for USB peripheral

Stephen Warren swarren at nvidia.com
Tue Dec 13 05:18:50 EST 2011


On 12/08/2011 02:24 PM, Simon Glass wrote:
> On Wed, Dec 7, 2011 at 3:46 PM, Stephen Warren <swarren at nvidia.com> wrote:
>> On 12/06/2011 02:23 PM, Simon Glass wrote:
...
>> I think the best implementation would be to enumerate everything solely
>> based on compatible flags, and allowing "usb start" to accept either an
>> alias name (which would be fixed) or a DT unit address or node name
>> (which would be fixed) or a controller index (which might vary based on
>> enumeration order) to select the controller.
>>
>> The next best implementation would be to enumerate solely based on
>> compatible flags, then sort the list based on alias, thus allowing alias
>> to cause a static order.
>>
>> However, enumerating based on alias, then enumerating based on
>> compatible flags and adding any missing nodes would be fine.
> 
> Well ok. Since this is basically a small *addition* to the code
> (scanning things that don't have an alias), and will have no effect
> with the device tree as included in this series, I would like to do
> this as a follow-on patch after the series. I hope you can live with
> that also?

I suppose it'll have to do.

It's totally the wrong way to go about it though, and will provide a bad
example that'll probably end up proliferating itself through the code
since it's the first example.

In other words rather than:

Now: Scan /aliases for USB, add then all.

Later: Scan device nodes for any that weren't in /aliases, add them all

I'd prefer to see:

Now: Scan /aliases for USB, add then all.

Later: Remove all the /aliases scanning code, fix the code to scan all
child nodes of the SoC node, find all nodes matching the USB compatible
flag, add them all. While adding a USB controller, check the /alias node
and honor any alias there if there is one.

-- 
nvpublic


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