Re: [PATCH 4/5] ASoC: SPEAr: remove custom DMA alloc compat function

[Rajeev kumar <rajeev-dlh.kumar@st.com>]

On 12/10/2013 2:30 PM, Lars-Peter Clausen wrote:
> On 12/10/2013 09:53 AM, Rajeev kumar wrote:
>> On 12/10/2013 1:15 PM, Lars-Peter Clausen wrote:
>>> On 12/10/2013 07:30 AM, Rajeev kumar wrote:
>>>> On 12/10/2013 2:47 AM, Lars-Peter Clausen wrote:
>>>>> On 12/09/2013 09:24 PM, Stephen Warren wrote:
>>>>>> From: Stephen Warren<swarren@nvidia.com>
>>>>>>
>>>>>> spear_pcm_request_chan() is almost identical to
>>>>>> dmaengine_pcm_compat_request_channel(), with the exception that the
>>>>>> latter:
>>>>>>
>>>>>> a) Assumes that the DAI DMA data is a struct snd_dmaengine_dai_dma_data
>>>>>>       pointer rather than some custom type.
>>>>>>
>>>>>> b) dma_data->filter_data rather than dma_data should be passed to
>>>>>>       snd_dmaengine_pcm_request_channel() as the filter data.
>>>>>>
>>>>>> Make minor changes to the SPEAr DAI drivers so that those two conditions
>>>>>> are met. This allows removal of the custom .compat_request_channel().
>>>>>>
>>>>>> Signed-off-by: Stephen Warren<swarren@nvidia.com>
>>>>>> ---
>>>>>>     include/sound/spear_dma.h   |  1 -
>>>>>>     sound/soc/spear/spdif_in.c  | 10 +++++++---
>>>>>>     sound/soc/spear/spdif_out.c | 10 +++++++---
>>>>>>     sound/soc/spear/spear_pcm.c | 21 +++++++--------------
>>>>>>     sound/soc/spear/spear_pcm.h |  4 +++-
>>>>>>     5 files changed, 24 insertions(+), 22 deletions(-)
>>>>>>
>>>>>> diff --git a/include/sound/spear_dma.h b/include/sound/spear_dma.h
>>>>>> index 1b365bfdfb37..65aca51fe255 100644
>>>>>> --- a/include/sound/spear_dma.h
>>>>>> +++ b/include/sound/spear_dma.h
>>>>>> @@ -29,7 +29,6 @@ struct spear_dma_data {
>>>>>>         dma_addr_t addr;
>>>>>>         u32 max_burst;
>>>>>>         enum dma_slave_buswidth addr_width;
>>>>>> -    bool (*filter)(struct dma_chan *chan, void *slave);
>>>>>>     };
>>>>>
>>>>> Hm, that spear_dma_data struct looks pretty much like
>>>>> snd_dmaengine_dai_dma_data. It's a bit hard to say how it is used exactly
>>>>> since the receiver of that struct doesn't seem to be upstream. Rajeev, how
>>>>> is this used? The data in spear_dma_data looks like it should be passed to
>>>>> the DMA driver via dmaengine_slave_config() rather than while requesting
>>>>> the
>>>>> channel.
>>>>>
>>>>> - Lars
>>>>> .
>>>>>
>>>>
>>>> The structure spear_dma_data is used to initialize dma parameters
>>>> received from
>>>> platform data which is required for dma slave configuration.
>>>
>>> Those parameters look like they should be configured using
>>> dmaengine_slave_config(). And not by passing them to the filter function.
>>>
>>> - Lars
>>>
>>> .
>>>
>>
>> Yes these parameter will be configured through dmaengine_slave_config().
>
> Ok, but this happens in the filter callback? Or is this piece just missing
> from the upstream driver at the moment? Do you think the code can be
> rewritten to use the generic snd_dmaengine_dai_dma_data struct?
>

Passing complete spear_dma_data is wrong in the filter callback, This 
needs to be modified. I will circulate a patch for this. The platform 
code for this also needs to be upstreamed.

Regards
Rajeev



> Thanks,
> - Lars
>
> .
>