Re: [PATCH 0/4] add minimal bcm2835-sdram driver

From: Martin Sperl
Date: Thu May 12 2016 - 12:03:08 EST



> On 12.05.2016, at 17:55, Stefan Wahren <stefan.wahren@xxxxxxxx> wrote:
>
> Hi,
>
>> Martin Sperl <kernel@xxxxxxxxxxxxxxxx> hat am 12. Mai 2016 um 17:28
>> geschrieben:
>>
>>
>>
>>> On 12.05.2016, at 16:50, Stefan Wahren <stefan.wahren@xxxxxxxx> wrote:
>>>
>>> Hi Martin,
>>>
>>>> kernel@xxxxxxxxxxxxxxxx hat am 12. Mai 2016 um 14:38 geschrieben:
>>>>
>>>>
>>>> From: Martin Sperl <kernel@xxxxxxxxxxxxxxxx>
>>>>
>>>> As the sdram clock is a critical clock to the system
>>>> the minimal bcm2835-sdram driver claims (and enables)
>>>> this clock and also exposes the corresponding sdram
>>>> registers via debugfs.
>>>
>>> sounds like this driver should fix an clock handling issue. Unfortunately
>>> this
>>> isn't a solution in case the driver is disabled.
>> Unfortunately there is no way around this - the driver has
>> to be enabled so that the sdram clock or the parent pll,
>> which typically is plld_core, never gets disabled.
>>
>> The only other option would be marking the clock as critical
>> for those legacy drivers.
>
> i would prefer this option. Since this would be more a fix we could get this
> faster in, it's more clear why we are doing that and less to review.
>
> Did i miss a drawback?

We had long discussions already on that - and HAND_OFF did not make
it into the kernel either.

I had hoped that this was simple enough.

Martin