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

[Markus Mitsch]

Hello,
sorry for the late answer. all my problems with optical out seem to
be solved with this. i still dont understand why without sigma delta
modulation the 44.1 khz did not work while all other sampling rates
were ok.
but now i can leave sdm on an did not see a sampling rate fail. thanks to all.

greetings
markus
Am Mi., 8. Aug. 2018 um 11:59 Uhr schrieb Chen-Yu Tsai <wens at csie.org>:
>
> Hi,
>
> On Sun, Jun 10, 2018 at 1:46 AM, Markus Mitsch
> <markusmitsch86 at googlemail.com> wrote:
> > 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.
>
> So it seems that the default mid-level bias current setting for PLL2
> interferes with sigma-delta modulation. Similarly, the VCO bias setting
> also interferes.
>
> Try zeroing out bits 16 ~ 25 in the PLL2 tuning register (0x01c2000c)
> with sigma delta on, and see if that fixes things.
>
> I'll send out a patch later.
>
> ChenYu
>
> > 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