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

[Simon Horman <horms@verge.net.au>]

On Fri, Feb 12, 2016 at 07:47:45PM +0300, Sergei Shtylyov wrote:
> On 02/10/2016 08:14 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.

> >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.

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) {
 		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))