Re: [PATCH v2 2/2] arm64: dts: qcom: Add msm8916 CoreSight components

[Mathieu Poirier]

On 8 May 2015 at 08:17, Ivan T. Ivanov <ivan.ivanov@xxxxxxxxxx> wrote:
>
> On Fri, 2015-05-08 at 08:13 -0600, Mathieu Poirier wrote:
>> On 8 May 2015 at 07:47, Ivan T. Ivanov ivanov@xxxxxxxxxx> wrote:
>> > On Fri, 2015-05-08 at 07:38 -0600, Mathieu Poirier wrote:
>> > > On 7 May 2015 at 09:36, Ivan T. Ivanov ivanov@xxxxxxxxxx> wrote:
>> > > > Add initial set of CoreSight components found on Qualcomm's 8x16 chipset.
>> > > >
>> > > >
>> > > > +       replicator@824000 {
>> > > > +               compatible = "qcom,coresight-replicator", "arm,primecell";
>> > >
>> > > Shouldn't it be "qcom,coresight-replicator1x" ?
>> > >
>> >
>> >
>> >
>> > True, I still wonder, why we have to have this compatible string?
>> > Drivers are probed by amba_id and "arm,primecell", after all.
>> >
>>
>> Drivers have their own compatible strings for historical reasons,
>> something I've been meaning to fix for a long time now...
>>
>
> Yep, I see that they have been platform drivers in the past, but now
> they are not, except coresight-replicator driver. IMHO, having
> additional compatible string could lead just to confusion.

I did a little more research on this and based on what I found in the
kernel it may not need "fixing" after all.  The majority of drivers
that do specify "arm,primecell" also specify a device-specific
compatible string.  And in the case of CoreSight devices were
implementers can do pretty much whatever they  want with the ID
strings, it is only a matter of time before we need to call something
like of_device_is_compatible() to fix a quirk.

Unless someone heavy asks to remove the device-specific compatible
strings I'd prefer keeping the current trend set forth by other
drivers and as such, will ask you to add the "1x" in this bindings.

Thanks,
Mathieu

>
> Regards,
> Ivan
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