Re: [PATCH v4 5/5] clk: rockchip: rk3588: add GATE_GRF clocks for I2S MCLK output to IO

[Diederik de Haas]

Hi Daniele,

On Tue Jun 23, 2026 at 3:23 PM CEST, Daniele Briguglio wrote:
>> md.l 0xfd58c318
>> fd58c318: 00000600
>
> Thanks. Bit 0 is clear there, so the I2S0 gate is open at the U-Boot
> prompt, after BL31 and before Linux. That matches the symptom: the
> firmware on your T6 leaves it open, and the kernel closes it once nothing
> references it.
>
> Given that, I think Heiko's suggestion makes sense here. Marking the four
> gates CLK_IGNORE_UNUSED keeps the kernel from disabling what the firmware
> already left open, and boards that reference _TO_IO still drive it through
> the consumer.

My suspicion that more RK3588 based boards would be broken is because NONE use
I2S0_8CH_MCLKOUT_TO_IO; they all use I2S0_8CH_MCLKOUT.
(And the testing was only done on not (yet?) upstreamed boards)

> Could you test that change if you get a chance? Just set the flag on the
> I2S0/1/2/3 _TO_IO gates in clk-rk3588.c and check your analog audio comes
> back. The series is already merged, so I'll send the fix as a separate
> follow-up patch, this evening if Heiko is fine with the approach.

I'm going to build a new kernel where I did ``s/0/CLK_IGNORE_UNUSED/`` 4 times
and I adjusted my NanoPC-T6 Plus board dts to use I2S0_8CH_MCLKOUT_TO_IO, while
I keep the LTS board dts to I2S0_8CH_MCLKOUT.
So IIUC that means I'd be testing both variants.

Cheers,
  Diederik