[U-Boot] [PATCH] arm: omap3: Enable clocks for peripherals only if they are used

[Igor Grinberg]

Hi Michael,

On 11/19/13 10:59, Michael Trimarchi wrote:
> Hi Igor
> 
> On Tue, Nov 19, 2013 at 9:49 AM, Michael Trimarchi
> <michael at amarulasolutions.com> wrote:
>> Hi Igor
>>
>> On Tue, Nov 19, 2013 at 9:24 AM, Igor Grinberg <grinberg at compulab.co.il> wrote:
>>> Hi Michael,
>>>
>>> On 11/18/13 16:10, Michael Trimarchi wrote:
>>>> Enable clocks for the peripherals only if they are used

This is not exactly what the patch does, right?
I would expect a better description of what you do in the patch
and what are the consequences of this patch.
May be some of the consequences can be avoided?

>>>>
>>>> Signed-off-by: Michael Trimarchi <michael at amarulasolutions.com>
>>>> ---
>>>>  arch/arm/cpu/armv7/omap3/clock.c        | 2 --
>>>>  arch/arm/include/asm/arch-omap3/clock.h | 2 --
>>>>  2 files changed, 4 deletions(-)
>>>>
>>>> diff --git a/arch/arm/cpu/armv7/omap3/clock.c b/arch/arm/cpu/armv7/omap3/clock.c
>>>> index 14fc7e8..1bc27bd 100644
>>>> --- a/arch/arm/cpu/armv7/omap3/clock.c
>>>> +++ b/arch/arm/cpu/armv7/omap3/clock.c
>>>> @@ -730,8 +730,6 @@ void per_clocks_enable(void)
>>>>               sr32(&prcm_base->fclken_cam, 0, 32, FCK_CAM_ON);
>>>>               sr32(&prcm_base->iclken_cam, 0, 32, ICK_CAM_ON);
>>>>       }
>>>> -     sr32(&prcm_base->fclken_per, 0, 32, FCK_PER_ON);
>>>> -     sr32(&prcm_base->iclken_per, 0, 32, ICK_PER_ON);
>>>
>>> Hmmm...
>>> Am I missing something or is this change breaks boards that
>>> currently rely on the peripheral clocks being enabled here?
>>>
>>
>> This change break boards that are not correctly configured.

I don't agree on this one.
This change breaks boards that are _correctly_ configured
prior to the patch.
As a consequence of this patch, there might be boards that
are not correctly configured and thus broken.
In other words, this patch breaks boards that rely on those clocks
being enabled.

>>
> 
> To be more clear, this change just enable clocks that are supposed
> to be used.

Well, if I read the patch correctly, it does not enable anything.
It removes the unconditional configuration of some clocks...

> Now that code was supposed to be removed long
> time ago.

Were there any discussions on this meter?
Can you please point me to a discussion on this?
Otherwise, the 'supposed' word here does not have a basis.

> 
> Michael
> 
>> Michael
>>
>>>>
>>>>       sdelay(1000);
>>>>  }
>>>> diff --git a/arch/arm/include/asm/arch-omap3/clock.h b/arch/arm/include/asm/arch-omap3/clock.h
>>>> index be669c1..1912cc9 100644
>>>> --- a/arch/arm/include/asm/arch-omap3/clock.h
>>>> +++ b/arch/arm/include/asm/arch-omap3/clock.h
>>>> @@ -27,8 +27,6 @@
>>>>  #define ICK_DSS_ON   0x00000001
>>>>  #define FCK_CAM_ON   0x00000001
>>>>  #define ICK_CAM_ON   0x00000001
>>>> -#define FCK_PER_ON   0x0003ffff
>>>> -#define ICK_PER_ON   0x0003ffff
>>>>
>>>>  /* Used to index into DPLL parameter tables */
>>>>  typedef struct {
>>>>
>>>
>>> --
>>> Regards,
>>> Igor.
>>
>>
>>
>> --
>> | Michael Nazzareno Trimarchi                     Amarula Solutions BV |
>> | COO  -  Founder
>> Cruquiuskade 47 |
>> | +31(0)851119172                                   Amsterdam 1018 AM NL |
> 

-- 
Regards,
Igor.