Re: [PATCH v2] DSPBRIDGE: use dm timer framework for gpt timers

[Omar Ramirez Luna <omar.ramirez@ti.com>]

On 4/28/2010 11:36 AM, Menon, Nishanth wrote:
> Kevin Hilman had written, on 04/28/2010 11:29 AM, the following:
>> Omar Ramirez Luna<omar.ramirez@ti.com>  writes:
>>
>>> On 4/28/2010 2:46 AM, Felipe Contreras wrote:
>>>> On Wed, Apr 28, 2010 at 4:29 AM, Omar Ramirez Luna<omar.ramirez@ti.com>   wrote:
>>>>> This patch switches to use DM timer framework instead of
>>>>> a custom one for GPT timers, currently dsp can make use of
>>>>> gpt 5, 6, 7 or 8.
>>>> I heard someone that was using gpt 8 for something else. Is it
>>>> possible to configure dsp-bridge to not use it?
>>>>
>>> There are two scenarios:
>>>
>>> 1. The request comes from the DSP side (afaik for video use case), the
>>> change should be in the DSP side binaries to request some other gpt
>>> instead. I don't know how possible is to get this changed.
>>>
>>> 2. bridge driver also requests gpt8 whenever a mmu fault is triggered,
>>> this to set a timer to interrupt the dsp after the mmu fault dump has
>>> been finished, I think this can be easily replaced in bridge to use
>>> some other gpt, but "1" is still there. (besides a new patch is needed
>>> to remove direct access to dm timer inside ue_deh and make it to go
>>> through dsp-clock)
>>
>> Why does Bridge care at all which specific timers it requests?  They
>> are all the same, with the exception of GPT1 which is in the WKUP
>> powerdomain and already used as the kernel clocksource.
>>
>> Bridge should just use the generic _request() instead of
>> _request_specific()
>>
> trouble I believe is that DSP BIOS uses a specific timer.
>

yes, dsp side wants:
bios --> GPT5 (only used during boot up -> baseimage load)
load monitoring --> GPT 6 (used while the dsp is awake)
AV Sync --> GPT 8 (based on use case)

to generate the interrupt for mmu fault case it needs one connected to 
the dsp interrupt line and only 5, 6, 7 or 8 apply.

Regards,

Omar