Messages in this thread | | | Subject | Re: [PATCH] ASoC: es8316: limit headphone mixer volume | From | Katsuhiro Suzuki <> | Date | Tue, 27 Aug 2019 00:25:07 +0900 |
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Hello Hans, Daniel,
Thank you for reviewing and comment.
On 2019/08/26 18:09, Hans de Goede wrote: > Hi, > > On 26-08-19 04:53, Daniel Drake wrote: >> On Mon, Aug 26, 2019 at 1:38 AM Hans de Goede <hdegoede@redhat.com> >> wrote: >>> On 24-08-19 23:04, Katsuhiro Suzuki wrote: >>>> This patch limits Headphone mixer volume to 4 from 7. >>>> Because output sound suddenly becomes very loudly with many noise if >>>> set volume over 4. >> >> That sounds like something that should be limited in UCM. >> >>> Higher then 4 not working matches my experience, see this comment from >>> the UCM file: alsa-lib/src/conf/ucm/codecs/es8316/EnableSeq.conf : >>> >>> # Set HP mixer vol to -6 dB (4/7) louder does not work >>> cset "name='Headphone Mixer Volume' 4" >> >> What does "does not work" mean more precisely? > > IIRC garbled sound. > >> I checked the spec, there is indeed something wrong in the kernel >> driver here. >> The db scale is not a simple scale as the kernel source suggests. >> >> Instead it is: >> 0000 – -12dB >> 0001 – -10.5dB >> 0010 – -9dB >> 0011 – -7.5dB >> 0100 – -6dB >> 1000 – -4.5dB >> 1001 – -3dB >> 1010 – -1.5dB >> 1011 – 0dB >> >> So perhaps we can fix the kernel to follow this table and then use UCM >> to limit the volume if its too high on a given platform? > > Yes that sounds like the right thing to do. Katsuhiro can you confirm that > using this table allows using the full scale ? note that the full scale now > has 9 steps rather then 8. >
I've finished testing this table on my board (RockPro64). Every values work well without garbled sound.
I checked address 0x16 register via /sys/kernel/debug/regmap too. The register values and dB (get from alsamixer) are the following if I increase headphone volume to max from min.
reg dB 0x16 scale ------------ 0x00 -12.00 0x11 -10.50 0x22 -9.00 0x33 -7.50 0x44 -6.00 0x88 -4.50 0x99 -3.00 0xaa -1.50 0xbb 0.00
And I found other problem, current code is inverted L/R volume. It's only in Headphone "mixer" volume. It seems Headphone "master" volume works correctly.
I'll fix these problems and send V2 patch set.
> Regards, > > Hans > >
Best Regards, Katsuhiro Suzuki
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