Re: [PATCH V2 6/6] spi/spi-pl022: Request/free DMA channels as and when required.

[Jassi Brar <jassisinghbrar-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]

On Thu, Aug 11, 2011 at 8:18 PM, Linus Walleij <linus.walleij-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> wrote:
> 2011/8/11 Jassi Brar <jassisinghbrar-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>:
>
>> Do you have any reason for using device pointer and strings, other
>> than just "because clock and regulator use them" ??
>
> Basically no.

Dear, I am speechless !!
Best of luck.

>>>> Do you propose to implement a string parser in the core ?!
>>>
>>> Yes, the clock and regulator framework already does that.
>>> But it is only used when you cannot pass in a struct device *
>>> directly, like from device tree.
>>
>> Dude, I have utter disrespect for using strings in a case such as
>> expressing requirements.
>
> It's mainly a strcmp(), and it's only comparing to the
> well-established namespace that all devices have anyway,
> due to the way the device model is done.
>
> Basically when binding clocks or regulators it's:
>
> struct device *dev;
> strcmp(map_string, dev_name(dev));
>
> By this time struct device exist of course, since
> it's the device driver calling to get its clock/regulator.
>
> dev_name() comes from <linux/device.h> and basically
> takes the kobject name or an optional initilizer name
> for the device. So the names are pretty static, you don't
> need to parse them, just compare.
I think I know why and how clkdev and regulator use strings.
Here we are talking about dmac possibly expressing 8 parameters
as strings, not just 2.


>> I have already explained how we can easily and in a _better_ way
>> do without them (again see my last reply to Vindo's setup).
>> Tell me 1 reason why using strings, in this case, would be better ?
>
> I have no other reasons than the above.
>
> People like Russell (clkdevice) and Liam Girdwood (regulator)
> who I know are smarter than me and have worked with
> these subsystems for years choose that model, so I trust
> their judgement.
Let me provide you even more 'ammunition'
ASoC and USB-Gadget employs strings too
Though only Regulators, ASoC and CLKDEV(?) really _have-to_
employ strings.
USB-Gadget use them mainly for historical reasons - we can very well
replace that scheme with bit-fields as I propose.

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