Re: [PATCH 1/2] backlight: pwm: don't call legacy pwm request for device defined in dt

[Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>]

Hi Thierry,

On 07.11.2014 15:48, Thierry Reding wrote:
> On Sat, Oct 11, 2014 at 04:46:25PM +0300, Vladimir Zapolskiy wrote:
>> Platform PWM backlight data provided by board's device tree should be
>> complete enough to successfully request a pwm device using pwm_get() API.
>>
>> Based on initial implementation done by Dmitry Eremin-Solenikov.
>>
>> Reported-by: Dmitry Eremin-Solenikov <dmitry_eremin@mentor.com>
>> Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
>> Cc: Thierry Reding <thierry.reding@gmail.com>
>> Cc: Jingoo Han <jg1.han@samsung.com>
>> Cc: Bryan Wu <cooloney@gmail.com>
>> Cc: Lee Jones <lee.jones@linaro.org>
>> ---
>>  drivers/video/backlight/pwm_bl.c |   14 +++++++-------
>>  1 file changed, 7 insertions(+), 7 deletions(-)
> 
> I don't really understand what this is supposed to do. The commit
> message doesn't make a very good job of explaining it either.
> 
> Can you describe in more detail what problem this fixes and why it
> should be merged?

thank you for review.

As it is shown by the code this particular change rejects fallback to
legacy PWM device request (which itself in turn is fixed in the next
commit) for boards with supplied DTS, "pwm-backlight" compatible node
and unregistered corresponding PWM device in that node.

I don't know if there is a good enough reason to register PWM backlight
device connected to some quite arbitrary PWM device, if no PWM device
information is given in the "pwm-backlight" compatible node, so I think
it makes sense to change the default policy.

--
With best wishes,
Vladimir