[PATCHv4 4/7] hwspinlock/core: add common OF helpers

[Bjorn Andersson]

On Sat, Mar 1, 2014 at 9:14 PM, Ohad Ben-Cohen <ohad at wizery.com> wrote:
> On Mon, Feb 10, 2014 at 9:14 PM, Suman Anna <s-anna at ti.com> wrote:
>> On 02/07/2014 04:49 PM, Bjorn Andersson wrote:
>>> It seems to be standard practice to pass the error value back to the
>>> consumer, so you should
>>> return ERR_PTR(ret); here instead of the NULL...
>>
>>
>> I have modelled the return values in this function based on the return
>> values in the existing hwspin_lock_request interfaces. I would need to
>> change those functions as well.
>>
>> Ohad,
>> Do you have any objections to the return code convention change?
>
> Unless strictly needed, I prefer we don't switch to the ERR_PTR code
> convention, as it reduces code readability and increases chances of
> user bugs.
>
> In our case, switching to ERR_PTR and friends seems only to optimize a
> few error paths, and I'm not sure it's a big win over simplicity.

When introducing the ability to reference a hwspin lock via a phandle
in device tree it makes a big difference to be able to differ between
the case of "initialization failed" or "device not yet probed"; so
that the client knows if it should fail or retry later.

Regards,
Bjorn