Hi Sameer, Hi Mark,
Am 2021-03-10 15:50, schrieb Sameer Pujar:
On 3/10/2021 4:00 AM, Michael Walle wrote:
Am 2021-03-09 17:27, schrieb Sameer Pujar:
On 3/9/2021 8:11 PM, Michael Walle wrote:
If "clocks = <&xxx>" is specified from the CPU or Codec component
device node, the clock is not getting enabled. Thus audio playback
or capture fails.
Fix this by populating "simple_dai->clk" field when clocks property
is specified from device node as well. Also tidy up by
re-organising
conditional statements of parsing logic.
Fixes: bb6fc620c2ed ("ASoC: simple-card-utils: add
asoc_simple_card_parse_clk()")
Cc: Kuninori Morimoto <kuninori.morimoto.gx@xxxxxxxxxxx>
Signed-off-by: Sameer Pujar <spujar@xxxxxxxxxx>
This actually breaks sound on my board
(arch/arm64/boot/dts/freescale/fsl-ls1028a-kontron-sl28-var3-ads2.dts).
The codec on this board (wm8904) has a fixed clock input (only
distinct
frequencies are supported) and uses the FLL of the codec to generate
the
desired sample rate.
It seems that after this patch the clock rate of the codecs clock
(rather
than the FLL) is tried to be changed. Which fails, because it
doesn't
support arbitrary frequencies.
Yes, after the given change the clock will be updated if "*mclk-fs"
property is specified.
DT you mentioned has property "simple-audio-card,mclk-fs = <256>",
which means you need a clock that is a function of sample rate. But
as
per above you want a fixed clock for MCLK. I think if you drop this
property, the clock updates won't happen. Earlier for your case, this
property was not used at all because the clock handle was not
populated.
You mean to drop the mclk-fs property? I can't do that because I
actually need a frequency of 256 * sample rate. But that doesn't
necessarily need to be the MCLK, because the codec itself has a
FLL/PLL which can be used to generate any frequency for a given
MCLK. So that is a valid scenario. See also commit 13409d27cb39
("ASoC: wm8904: configure sysclk/FLL automatically").
If I read this correctly below is the configuration you need,
SoC -> MCLK(fixed rate) -> PLL(wm8904) -> PLL output (256 * fs) ->
sysclk
From the doc simple-card.txt, "simple-audio-card,mclk-fs" is a scaling
factor for MCLK and hence I am not sure if it is correct to have
"*mclk-fs" property when MCLK is fixed. In simple cases, codec sysclk
direclty depends on MCLK and set_sysclk() callback helps. Your case
requires PLL configuration and set_pll() may be a better alternative.
However simple-card does not offer this yet. But even if this is
added, there should be a way to suggest PLL output requirement as a
function of sample rate.
But its also a scaling factor for the sysclk, then maybe the property
has a wrong name. And you might be right with your suggestion, but
as I said, this breaks sound on my board and whats even worse, it
breaks it for older kernel too, because of the Fixes tag.
Btw I'm pretty sure, the MCLK was enabled and disabled depending on
whether there was an audio stream, the last time I've measured the
clock.
Mark, can this patch please be reverted (with a Fixes tag) until
a proper fix is found which satisfies both needs?
-michael
