Re: [PATCH RFC 12/12] PoC: arm64: dts: imx93-11x11-frdm: add multiple vdevs

[Francesco Valla <francesco@valla.it>]

Hi Alexander,

On Fri, Sep 25, 2026 at 10:39:46AM +0200, Alexander Stein wrote:
> Am Mittwoch, 16. September 2026, 23:10:57 CEST schrieb Francesco Valla:
> > Add rings for multiple vdevs, as well as the required virtio nodes for
> > I2C, SPI and GPIO functionalities. On top of that, add example
> > peripherals using all of them.
> > 
> > NOTE: this is a Proof-Of-Concept, not meant to be integrated!
> > 
> > Signed-off-by: Francesco Valla <francesco@valla.it>
> 
> Just a general question, unrelated to virtio, but related to AMP: How do you
> manage the clocks, so that Linux doesn't disable clocks needed by the
> Cortex-M?
> 
> Best regards
> Alexander
>

Clock management for remote processors on i.MX93 (and other i.MX parts)
is... not really a management, AFAICT. If you want to use a remote
processor, the mcore_booted argument shall be specified in the kernel
cmdline; this forces the clock management driver to leave root clock
gates enabled for *everything*, leaving the possibility for the remote
processor to use anything it needs.

While out of scope for the current patchset, some work in this field
certainly is on my (long) TODO list.

Current implementation can be seen in [1] and [2].


Regards,
Francesco


[1] https://elixir.bootlin.com/linux/v7.2.7/source/drivers/clk/imx/clk-imx93.c
[2] https://elixir.bootlin.com/linux/v7.2.7/source/drivers/clk/imx/clk-composite-93.c#L83