Re: [PATCH v2 5/5] ARM: dts: r8a7794: add sound support

[Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>]

On 02/12/2016 10:33 PM, Simon Horman wrote:

>>>>>> Sorry for my un-ordered response
>>>>>>
>>>>>>> Define the generic R8A7794 part of  the sound device node.
>>>>>>> This sound device  is a complex one and comprises the Audio Clock Generator
>>>>>>> (ADG), Sampling Rate Converter Unit (SCU), Serial Sound Interface [Unit]
>>>>>>> (SSI[U]), and Audio DMAC-Peripheral-Peripheral.
>>>>>>> It is up  to the board file to enable the device.
>>>>>>>
>>>>>>> This patch is based on the R8A7791 sound work by Kuninori Morimoto.
>>>>>>>
>>>>>>> Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
>>>>>> (snip)
>>>>>>> +		rcar_sound,src {
>>>>>>> +			src1: src@1 {
>>>>>>> +				interrupts = <GIC_SPI 353 IRQ_TYPE_LEVEL_HIGH>;
>>>>>>> +				dmas = <&audma0 0x87>, <&audma0 0x9c>;
>>>>>>> +				dma-names = "rx", "tx";
>>>>>>> +			};
>>>>>>> +			src2: src@2 {
>>>>>>> +				interrupts = <GIC_SPI 354 IRQ_TYPE_LEVEL_HIGH>;
>>>>>>> +				dmas = <&audma0 0x89>, <&audma0 0x9e>;
>>>>>>> +				dma-names = "rx", "tx";
>>>>>>> +			};
>>>>>>> +			src3: src@3 {
>>>>>>> +				interrupts = <GIC_SPI 355 IRQ_TYPE_LEVEL_HIGH>;
>>>>>>> +				dmas = <&audma0 0x8b>, <&audma0 0xa0>;
>>>>>>> +				dma-names = "rx", "tx";
>>>>>>> +			};
>>>>>>> +			src4: src@4 {
>>>>>>> +				interrupts = <GIC_SPI 356 IRQ_TYPE_LEVEL_HIGH>;
>>>>>>> +				dmas = <&audma0 0x8d>, <&audma0 0xb0>;
>>>>>>> +				dma-names = "rx", "tx";
>>>>>>> +			};
>>>>>>> +			src5: src@5 {
>>>>>>> +				interrupts = <GIC_SPI 357 IRQ_TYPE_LEVEL_HIGH>;
>>>>>>> +				dmas = <&audma0 0x8f>, <&audma0 0xb2>;
>>>>>>> +				dma-names = "rx", "tx";
>>>>>>> +			};
>>>>>>> +			src6: src@6 {
>>>>>>> +				interrupts = <GIC_SPI 358 IRQ_TYPE_LEVEL_HIGH>;
>>>>>>> +				dmas = <&audma0 0x91>, <&audma0 0xb4>;
>>>>>>> +				dma-names = "rx", "tx";
>>>>>>> +			};
>>>>>>> +		};
>>>>>>
>>>>>> I think this can't work correctly, because driver is assuming
>>>>>> DT has all channles (from 0). (see linux/sound/soc/sh/rcar/src.c :: rsnd_src_probe)
>>>>>> Can you adds dummy src0 with some comments ? or fix src.c driver ?
>>>>>
>>>>> I would prefer the driver to be fixed (I had a similar patchset locally
>>>>> and I found it doesn't work).
>>>>
>>>>     You mean you had R8A7794 sound patch set too?
>>>
>>> Yes, I was working on it recently.
>>> I suppose we should coordinate these things in future to avoid
>>> duplicated effort.
>>
>>     Yes, seems a good idea now. :-)
>>
>>>>> The reason is that DT should describe
>>>>> the hardware rather than the current state of the software.
>>>>
>>>>     Yes, of course. Just tell me do I have to fix the driver *before* this
>>>> patch set is accepted?
>>
>>> I did not entirely get to the bottom of the problem, but I think that at
>>> the very least something needs to be done about the for_each_rsnd_src()
>>> loop in rsnd_src_probe.
>>
>>     It's not that it replies to my question. :-)
>>     So you're looking at this issue yourself?
>
> I have not got very far, as you can see, but I was planning to look into it.
> I don't mind if you want to do so.

    After consultation with the management, I'm going to look into this issue 
myself. :-)

>>> My, obviously not satisfactory, hack around there being no src0 was as follows.
>>>
>>> diff --git a/sound/soc/sh/rcar/src.c b/sound/soc/sh/rcar/src.c
>>> index 68b439ed22d7..58a447b0785b 100644
>>> --- a/sound/soc/sh/rcar/src.c
>>> +++ b/sound/soc/sh/rcar/src.c
>>> @@ -1072,7 +1072,7 @@ int rsnd_src_probe(struct platform_device *pdev,
>>>
>>>   	for_each_rsnd_src(src, priv, i) {
>>
>>     Which tree is this? The recent devel branch of renesas.git has
>> for_each_child_of_node() here...
>
> renesas-devel-20160118-v4.4

    Ah! :-)

> I guess the code in question updated in v4.5-rcX.

    Probably...

[...]

MBR, Sergei