Re: [PATCH 1/2] ASoC: simple-card-utils: add ignore_zero_sysclk flag

Mark Brown
2026-03-18T11:56:37Z

[-- Attachment #1: Type: text/plain, Size: 1428 bytes --]

On Wed, Mar 18, 2026 at 02:36:42PM +0530, Sheetal . wrote:
> On 18-03-2026 04:32, Kuninori Morimoto wrote:

> > > If the driver simply can't tolerate disabling the sysclk it seems like
> > > it would be easier to just have the driver directly ignore attempts to
> > > do so rather than adding this flag which the driver has to set only to
> > > get it passed in?

> > Agree.
> > I think this commit can help you ?

> > 1e1a2ef95b571825ca9c0113f6bef51e9cec98b0
> > ("ASoC: da7213: Avoid setting PLL when closing audio stream")

> Thank you for the feedback and the da7213 reference.

> The concern with the per-codec approach is that this affects any codec with
> a set_dai_sysclk that forwards the frequency to clk_set_rate(). Since any
> codec can be connected to Tegra platforms, and MCLK is provided by the SoC
> to external codecs, when clk_set_rate(..., 0) reaches the BPMP firmware, it
> raises a fault for rates below the hardware minimum. Fixing this per-codec
> would require individual patches for each.

Since in the clock API clk_get_rate() maps onto clk_disable() those
drivers ought to be fixed anyway - perhaps we need some helpers for this
since it does look like we have some issues here. Either the driver
should ignore the disable (possibly due to already refcounting the use
of the clock and disabling/enabling without machine driver help) or it
should translate a rate of 0 to a disable.

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 488 bytes --]