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

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

On 02/12/2016 09:43 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?

> 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...

>   		snprintf(name, RSND_SRC_NAME_SIZE, "%s.%d",
> -			 SRC_NAME, i);
> +			 SRC_NAME, i + 1);
>
>   		clk = devm_clk_get(dev, name);
>   		if (IS_ERR(clk))

MBR, Sergei