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

From: Simon Horman <horms@verge.net.au>
To: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Cc: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>,
	linux-renesas-soc@vger.kernel.org, robh+dt@kernel.org,
	pawel.moll@arm.com, mark.rutland@arm.com,
	ijc+devicetree@hellion.org.uk, galak@codeaurora.org,
	devicetree@vger.kernel.org, magnus.damm@gmail.com,
	linux@arm.linux.org.uk, linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v2 5/5] ARM: dts: r8a7794: add sound support
Date: Wed, 17 Feb 2016 14:38:48 +0900	[thread overview]
Message-ID: <20160217053848.GC11534@verge.net.au> (raw)
In-Reply-To: <56BE3912.9000601@cogentembedded.com>

On Fri, Feb 12, 2016 at 10:57:06PM +0300, Sergei Shtylyov wrote:
> 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. :-)

Excellent.

FWIW, I can test anything you come up with for the r8a7794 an alt board
or post patches for it once you have r8a7794/silk sorted out.

> >>>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