Re: [meta-freescale] linux-fsl 5.10 kernels don't appear to have multi-lane in sound/soc/fsl/fsl_sai.c

REFERRED_PROVIDER_virtual/kernel = "linux-fslc-imx"Hi Andrey,

On Wed, Oct 27, 2021 at 12:01 PM Brian Hutchinson via lists.yoctoproject.org
<[email protected]> wrote:

> Hey Andrey,
>
> On Wed, Oct 27, 2021 at 10:37 AM Andrey Zhizhikin <[email protected]>
> wrote:
>
>> Hello Brian,
>>
>> On Wed, Oct 27, 2021 at 3:24 PM Brian Hutchinson <[email protected]>
>> wrote:
>> >
>> > Hi Andrey,
>> >
>> >
>> > On Wed, Oct 27, 2021 at 9:01 AM Andrey Zhizhikin <[email protected]>
>> wrote:
>> >>
>> >> Hello Brian,
>> >>
>> >> On Wed, Oct 27, 2021 at 2:45 PM Brian Hutchinson <[email protected]>
>> wrote:
>> >> >
>> >> >
>> >> >
>> >> > On Wed, Oct 27, 2021 at 8:18 AM Fabio Estevam <[email protected]>
>> wrote:
>> >> >>
>> >> >> Hi Brian,
>> >> >>
>> >> >> On Tue, Oct 26, 2021 at 11:10 AM Brian Hutchinson <
>> [email protected]> wrote:
>> >> >> >
>> >> >> >
>> >> >> >
>> >> >> > On Tue, Oct 26, 2021 at 10:07 AM Brian Hutchinson via
>> lists.yoctoproject.org <[email protected]>
>> wrote:
>> >> >> >>
>> >> >> >> Hi,
>> >> >> >>
>> >> >> >> First, forgive me for posting a link in an post with no context
>> ... I hit a wrong button and accidentally sent before ready.
>> >> >> >>
>> >> >> >> Bottom line up front.  How can I get a 5.10 kernel with
>> multi-lane support for IMX8MM?
>> >> >> >>
>> >> >> >> We use linux-fsl 5.4 on a IMXMM based board and have recently
>> stepped up to linux-fsl 5.10 and the sound/fsl/fsl_sai.c has no support for
>> "multi-lane" anymore which breaks our code.
>> >> >> >>
>> >> >> >> I figure this is simply a case where things in linux-imx are new
>> and just not picked up in linux-fslc yet but wondering if it's possible to
>> get multi-lane support in a 5.10 kernel for the IMX8MM.
>> >> >> >>
>> >> >> >> I still don't quite fully understand how all the releases work,
>> the linux-imx releases appear to be for newer boards and don't necessarily
>> support the older boards from what I'm seeing.
>> >> >> >>
>> >> >> >> Thanks for any advice/guidance.
>> >> >> >>
>> >> >> >> Regards,
>> >> >> >>
>> >> >> >> Brian
>> >> >> >
>> >> >> >
>> >> >> > And that link I accidentally posted by itself
>> https://source.codeaurora.org/external/imx/linux-imx/tree/sound/soc/fsl/fsl_sai.c?h=lf-5.10.y
>> >> >> >
>> >> >> > ... is the reference I mentioned where I see multi-lane support
>> in linux-imx 5.10.
>> >> >>
>> >> >> With the mainline SAI driver, it is possible to use several
>> channels.
>> >> >> Not sure what you mean by "multi-lane" in your use-case.
>> >> >>
>> >> >> Please check:
>> >> >>
>> https://bootlin.com/blog/eight-channels-audio-on-i-mx7-with-pcm3168/
>> >> >
>> >> >
>> >> > I hoped folks would know what I was talking about without getting
>> too far into the weeds.  But I guess I need to explain more.
>> >> >
>> >> > The older 5.4 kernels (and even 4 series kernels) had a
>> imx8mm-evk.dts sai section that looked like this:
>> >> >
>> >> > &sai1 {
>> >> >        pinctrl-names = "default";
>> >> >        pinctrl-0 = <&pinctrl_sai1>;
>> >> >        assigned-clocks = <&clk IMX8MM_CLK_SAI1>;
>> >> >        assigned-clock-parents = <&clk IMX8MM_AUDIO_PLL1_OUT>;
>> >> >        assigned-clock-rates = <24576000>;
>> >> >        clocks = <&clk IMX8MM_CLK_SAI1_IPG>, <&clk IMX8MM_CLK_DUMMY>,
>> >> >                <&clk IMX8MM_CLK_SAI1_ROOT>, <&clk IMX8MM_CLK_DUMMY>,
>> >> >                <&clk IMX8MM_CLK_DUMMY>, <&clk IMX8MM_AUDIO_PLL1_OUT>,
>> >> >                <&clk IMX8MM_AUDIO_PLL2_OUT>;
>> >> >        clock-names = "bus", "mclk0", "mclk1", "mclk2", "mclk3",
>> "pll8k", "pll11k";
>> >> >        fsl,sai-multi-lane;
>> >> >        fsl,dataline,dsd = <0 0xff 0xff 2 0xff 0x11>;
>> >> >        fsl,sai-synchronous-rx;
>> >> >        dmas = <&sdma2 0 25 0>, <&sdma2 1 25 0>;
>> >> >        #sound-dai-cells = <0>;
>> >> >        status = "okay";
>> >> > };
>> >> >
>> >> > ... which has fsl,sai-multi-lane support.
>> >> >
>> >> > The current linux-fslc 5.10 kernel does not have fsl,sai-multi-lane
>> support.
>> >>
>> >> linux-fslc-imx kernel recipe on the [master] branch on meta-freescale
>> >> provides a kernel, which has linux-imx as a base and latest LTS
>> >> applied on top.
>> >>
>> >> Assuming you're building now off the [master] branch and do not set
>> >> the IMX_DEFAULT_BSP to any value anywhere in your conf files - you
>> >> will be building a Mainline BSP (see [1]), which does select
>> >> linux-fslc as a preferred provider for your kernel, see [2].
>> >>
>> >> You can try to either switch your BSP to NXP one by setting
>> >> IMX_DEFAULT_BSP = "nxp", or switch your kernel provider to
>> >> "linux-fslc-imx" one.
>> >
>> >
>> > I really would like to stick with linux-fslc since that's what we've
>> been using for more than a year now.  Kind of scared to switch back to
>> linux-fslc-imx (I'll try to do better with my terminology) but if you guys
>> think that's best then I'll try it.  Worried that our custom apps might be
>> impacted by the switch.
>> >
>> >>
>> >> As a quick GIT grep in the linux-fslc repo on [5.10-2.1.x-imx] branch:
>> >> git grep sai-multi-lane
>> >> arch/arm64/boot/dts/freescale/imx8mm-evk-ak4497.dts:
>> fsl,sai-multi-lane;
>> >> arch/arm64/boot/dts/freescale/imx8mm-evk.dtsi:  fsl,sai-multi-lane;
>> >> arch/arm64/boot/dts/freescale/imx8mp-ab2.dts:   fsl,sai-multi-lane;
>> >> arch/arm64/boot/dts/freescale/imx8mq-evk-ak4497.dts:
>> fsl,sai-multi-lane;
>> >> arch/arm64/boot/dts/freescale/imx8mq-evk.dts:   fsl,sai-multi-lane;
>> >> sound/soc/fsl/fsl_sai.c:        if (of_find_property(np,
>> >> "fsl,sai-multi-lane", NULL))
>> >>
>> >> Guess this is what you're looking for, right?
>> >
>> >
>> > I'd be ok with doing a build of just the kernel on master branch as
>> long as it supports imx8mm-evk (what our board is based on) but the rest of
>> our rootfs is based on Dunfell release.
>> >
>> > So if I'm following you correctly, you're saying the linux-fslc repo
>> has imx 5.10 with multi-lane in it.
>>
>> There are 2 kernel repositories here at play, namely:
>> - linux-fslc from Freescale GitHub
>> - linux-imx from CodeAurora
>>
>> They both stem from stable korg, but using different strategy to evolve.
>>
>> linux-imx is an NXP kernel fork, which they use to commit their
>> internal patches on top of some stable release. In case of 5.10 - it
>> is v5.10.54 from stable korg, which resides on [lf-5.10.y] branch.
>>
>> linux-fslc is combination of various branches, and if we look at the
>> 5.10 - there is a corresponding branch [5.10.x+fslc], and it is
>> practically a vanilla 5.10.y kernel from stable korg, with only
>> handful of patches on top.
>>
>> If I to examine this like that:
>> $ git log --oneline --no-merges  stable/linux-5.10.y..5.10.x+fslc | wc -l
>> 9
>>
>> As one can see, it has only 9 patches on top of stable korg.
>>
>> What comes in addition inside linux-fslc repository, is the branch
>> [5.10-2.1.x-imx], which is a combination of [lf-5.10.y] branch from
>> linux-imx repo and latest stable patch applied on top of it (with
>> merge conflict resolution, of course).
>>
>> When examined, it brings the following:
>> $ git log --oneline  --no-merges stable/linux-5.10.y..5.10-2.1.x-imx  |
>> wc -l
>> 5456
>>
>> Here we see, that there is a substantial difference in terms of number
>> of patches applied. It might be a new functionality (like your desired
>> multi-lane support), but can also contain a code in question, which
>> might not work for all scenarios you're applying your kernel to.
>>
>> Hope that clears it a bit, and would help you to drive your decision
>> further on which kernel to use.
>>
>> >
>> > How come linux-fslc 5.10 doesn't have it?  Is it a case where imx
>> released it later and hasn't worked it's way into linux-fslc yet?
>>
>> That is the trick: you most probably used the NXP-based up-merged
>> branch in your BSP, but now when switched to new Yocto release - you
>> received a vanilla kernel, which does not have those NXP patches
>> applied.
>>
>
> So I was in error.  I looked back at the local.conf where our 5.4 kernel
> came from that we are happy with (and has multi-lane) and it was
> linux-fslc-imx so I guess it's linux-fslc with some imx releases merged in.
>
> When I switched to 5.10 in hardknott it looks like it pulled in linux-fslc
> by default which looks pretty vanilla as you mentioned.
>
> So I'll try what you said about "You can try to either switch your BSP to
> NXP one by setting
> IMX_DEFAULT_BSP = "nxp", or switch your kernel provider to
> "linux-fslc-imx" one."
>
> To try and get a linux-fslc-imx 5.10 build and see if it's got multi-lane
> in it.  I was using hardknott when I originally got 5.10 so don't know if I
> need to do a repo sync to get newer stuff or checkout master but would only
> be interested in getting kernel and keeping our Dunfell based rootfs.
>
> I'll go try some stuff.  Thanks for the input and advice.
>

So I did a repo sync in my hardknott checkout.  Then changed to
IMX_DEFAULT_BSP = "nxp" in imx8mm-evk.inc and added
PREFERRED_PROVIDER_virtual/kernel
= "linux-fslc-imx" in local.conf and kicked off a virtual/kernel build.
Looks like it's pulling down linux-fslc-imx-5.10.69.  So hopefully that's
ok, if not I guess I'll have to look at master but I don't want to be too
bleeding edge if you know what I mean.

... and it just finished building as I was typing this and it looks like it
does have multi-lane support in fsl_sai.c

Again, thanks for the info/ideas.

Regards,

Brian