Re: [PATCH v7 06/11] arm64: dts: ti: k3-am62a7-sk: Enable IPC with remote processors

Nishanth Menon
2025-04-21T11:40:51Z

On 10:04-20250419, Bryan Brattlof wrote:
> On April 15, 2025 thus sayeth Judith Mendez:
> > From: Devarsh Thakkar <devarsht@ti.com>
> >
> > For each remote proc, reserve memory for IPC and bind the mailbox
> > assignments. Two memory regions are reserved for each remote processor.
> > The first region of 1MB of memory is used for Vring shared buffers
> > and the second region is used as external memory to the remote processor
> > for the resource table and for tracebuffer allocations.
> >
> > Signed-off-by: Devarsh Thakkar <devarsht@ti.com>
> > Signed-off-by: Hari Nagalla <hnagalla@ti.com>
> > Signed-off-by: Judith Mendez <jm@ti.com>
> > Acked-by: Andrew Davis <afd@ti.com>
> > Reviewed-by: Beleswar Padhi <b-padhi@ti.com>
> > Reviewed-by: Jai Luthra <jai.luthra@ideasonboard.com>
> > ---
> > arch/arm64/boot/dts/ti/k3-am62a7-sk.dts | 96 +++++++++++++++++++++++--
> > 1 file changed, 90 insertions(+), 6 deletions(-)
> >
> > diff --git a/arch/arm64/boot/dts/ti/k3-am62a7-sk.dts b/arch/arm64/boot/dts/ti/k3-am62a7-sk.dts
> > index 1c9d95696c839..7d817b447c1d0 100644
> > --- a/arch/arm64/boot/dts/ti/k3-am62a7-sk.dts
> > +++ b/arch/arm64/boot/dts/ti/k3-am62a7-sk.dts
> > @@ -52,6 +52,42 @@ linux,cma {
> > linux,cma-default;
> > };
> >
> > + c7x_0_dma_memory_region: c7x-dma-memory@99800000 {
> > + compatible = "shared-dma-pool";
> > + reg = <0x00 0x99800000 0x00 0x100000>;
> > + no-map;
> > + };
> > +
> > + c7x_0_memory_region: c7x-memory@99900000 {
> > + compatible = "shared-dma-pool";
> > + reg = <0x00 0x99900000 0x00 0xf00000>;
> > + no-map;
> > + };
> > +
>
> I know this has been a push for our IPC and MCU+ teams for a couple
> windows now, though I do want to point out that some AM62A devices
> (AM62A12AQMSIAMBRQ1) will not even have a C7x.
>
> It's relatively easy to cut nodes out that describe the hardware in the
> bootloaders, but once we start configuring them to demo something it
> becomes impossible to unwind that during boot.
>
> We can clam we only support the superset devices but I just wanted to
> make this email so I could point people to it when they inevitably ask
> why their parts do not work out of the box with Linux.
>
> Naked-by: Bryan Brattlof <bb@ti.com>

I am confused. I do not see support for AM62A1 in upstream. We have
AM62A7-SK in upstream. I am not sure what direction you are suggesting
here.

--
Regards,
Nishanth Menon
Key (0xDDB5849D1736249D) / Fingerprint: F8A2 8693 54EB 8232 17A3 1A34 DDB5 849D 1736 249D