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@renesas.com Signed-off-by: Sameer Pujar spujar@nvidia.com
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