[alsa-devel] [linux-sunxi] [BUG] On Allwinner A20 Board Cubietruck distorted SPDIF opical output

[Markus Mitsch]

hi.

i posted my answer wrong so here is my finding:
i made the output work by disabling the sigma delta modulation.
after compiling the kernel  i can output through spdif with any rate.

greetings
markus

2018-05-26 18:38 GMT+02:00 Markus Mitsch <markusmitsch86 at googlemail.com>:
> 2018-05-26 16:57 GMT+02:00 Markus Mitsch <markusmitsch86 at googlemail.com>:
>> 2018-05-23 17:12 GMT+02:00 Code Kipper <codekipper at gmail.com>:
>>> Hi All,
>>> I can see that the problem was introduced somewhere here
>>>
>>> DOESN'T WORK
>>> ffc3eb6f3a83 Merge tag 'sunxi-clk-for-4.15' of
>>> https://git.kernel.org/pub/scm/linux/kernel/git/sunxi/linux into
>>> clk-next
>>> ae74ac082886 Merge tag 'clk-v4.15-exynos-pm' of
>>> git://git.kernel.org/pub/scm/linux/kernel/git/snawrocki/clk into
>>> clk-next
>>> faa865f18cb7 Merge tag 'clk-v4.15-samsung' of
>>> git://git.kernel.org/pub/scm/linux/kernel/git/snawrocki/clk into
>>> clk-next
>>> f09a6b86fdae Merge tag 'clk-renesas-for-v4.15-tag1' of
>>> git://git.kernel.org/pub/scm/linux/kernel/git/geert/renesas-drivers
>>> into clk-next
>>> 4328a2186e51 clk: sunxi-ng: sun4i: Export video PLLs
>>> 553c7d5ba2fe clk: sunxi-ng: Add A83T display clocks
>>> 7679eb20353d clk: samsung: Add a separate driver for Exynos4412 ISP clocks
>>> 8ca8ac102484 clk: samsung: Add dt bindings for Exynos4412 ISP clock controller
>>> 75920aac275a clk: samsung: Instantiate Exynos4412 ISP clocks only when available
>>> 24ea78a09f89 clk: sunxi-ng: sun8i: a23: Use sigma-delta modulation for audio PLL
>>> ee6501d69217 clk: sunxi-ng: sun6i: Use sigma-delta modulation for audio PLL
>>> 042f7f8f9715 clk: sunxi-ng: sun5i: Use sigma-delta modulation for audio PLL
>>> de3448519194 clk: sunxi-ng: sun4i: Use sigma-delta modulation for audio PLL
>>> a5e3e2b2ef85 clk: sunxi-ng: sun8i: h3: Use sigma-delta modulation for audio PLL
>>> 392ba5fafcdf clk: sunxi-ng: nm: Add support for sigma-delta modulation
>>> 05d2eaac96d4 clk: sunxi-ng: Add sigma-delta modulation support
>>> 4cdbc40d64d4 clk: sunxi-ng: nm: Check if requested rate is supported
>>> by fractional clock
>>> d51fe3ba9773 clk: sunxi-ng: sun5i: Fix bit offset of audio PLL post-divider
>>> 4e8975cbb516 clk: samsung: exynos5433: mark PM functions as __maybe_unused
>>> a4f21e9ceb5c clk: samsung: Remove obsolete clkdev alias support
>>> 45d882daf88a clk: samsung: Add explicit MPLL, EPLL clkdev aliases in
>>> S3C2443 driver
>>> cd05417f728b clk: samsung: Rework clkdev alias handling in S3C2443 driver
>>> efea8d377184 clk: samsung: Rework clkdev alias handling in Exynos5440 driver
>>> 36ba48240b19 clk: samsung: Drop useless alias in Exynos5420 clk driver
>>> 29964890f31c clk: samsung: Remove clkdev alias support in Exynos5250 clk driver
>>> 6de08891c896 clk: samsung: Remove double assignment of CLK_ARM_CLK in
>>> Exynos4 driver
>>> 58f4a5ff3a62 clk: samsung: Remove clkdev alias support in Exynos4 clk driver
>>> c9194fb623b0 clk: samsung: Remove support for obsolete Exynos4212 CPU clock
>>> d5cd103b06f9 clk: samsung: Remove support for Exynos4212 SoCs in
>>> Exynos CLKOUT driver
>>> 7c4f63ec94a1 clk: sunxi-ng: a83t: Fix invalid csi-mclk mux offset
>>> WORKS
>>> 0a4e632b6f9d Merge branch 'clk-fixes' into clk-next
>>>
>>> BR,
>>> CK
>>>
>>>
>>> On 22 May 2018 at 21:27, Code Kipper <codekipper at gmail.com> wrote:
>>>> Hi Markus,
>>>> I've been able to reproduce this on my A31 board with linux-next(plays
>>>> at 44100 but not at 96K)so it is an issue. I also tested the same code
>>>> on my A64 and it worked fine, The blocks are very similar so it maybe
>>>> a clocking issue, I'll look into this.
>>>> BR,
>>>> CK
>>>>
>>>> On 21 May 2018 at 20:17, Markus Mitsch <markusmitsch86 at googlemail.com> wrote:
>>>>> 2018-05-21 15:17 GMT+02:00 Maxime Ripard <maxime.ripard at bootlin.com>:
>>>>>> On Mon, May 21, 2018 at 02:43:55PM +0200, Markus Mitsch wrote:
>>>>>>> 2018-05-21 11:43 GMT+02:00 Markus Mitsch <markusmitsch86 at googlemail.com>:
>>>>>>> >>> Hello,
>>>>>>> >>>
>>>>>>> >>> i have a new problem. if i want to output sound from optical i get
>>>>>>> >>> distorted sound. At 44.1 khz its like an old vinly, but at 48 khz and
>>>>>>> >>> higher it is very bad. thanks in advance for your time.
>>>>>>> >
>>>>>>> >> Hi Markus,
>>>>>>> >> I haven't tested it for a while but when I did it worked as high as
>>>>>>> >> 96K with no issues. Does it work ok with the original cubietruck
>>>>>>> >> software?,
>>>>>>> >> CK
>>>>>>> >
>>>>>>> > Hello,
>>>>>>> > i am using arch linux with mainline kernel 4.16.8. parhaps i can try
>>>>>>> > today with official image.
>>>>>>> > mfg
>>>>>>>
>>>>>>> Hi.
>>>>>>> So, with debian image from 2014 with 3.4.79 kernel the sound is clear
>>>>>>> up to 96 khz.
>>>>>>
>>>>>> You said that it is a new problem, when was it introduced? Could you
>>>>>> bisect the issue?
>>>>>>
>>>>>> Maxime
>>>>>
>>>>> Hello.
>>>>> I dont know since when this problem appears. When saying "new" i
>>>>> refered to my older post. I tried to look into the dts file and the
>>>>> code
>>>>> but i am afraid this is a bit too high for me. I can say that the
>>>>> analog output works, even at high sampling rates.
>>>>> And I have read something about a clock source could be the problem.
>>>>> I'm sorry I can't tell you any more.
>>>>>
>>>>> mfg
>>>>> Markus
>>
>> Hello,
>> i tried undoing part of the commit
>> de3448519194 clk: sunxi-ng: sun4i: Use sigma-delta modulation for audio PLL
>> by setting the value for the divider from 1 to 4 again on both places.
>> with no success.
>>
>> markus
>
> i now had a little success. the output works!!
> i disabled the sigma-delta support by making
> ccu_sdm_helper_enable in drivers/clk/sunxi-ng/ccu_sdm.c  return imediately.
>
> markus