Re: [PATCH 5/7] dmaengine: sh: rz-dmac: Add suspend to RAM support

[Geert Uytterhoeven]

Hi Biju,

On Thu, 5 Feb 2026 at 14:30, Biju Das <biju.das.jz@xxxxxxxxxxxxxx> wrote:
> > From: Claudiu Beznea <claudiu.beznea@xxxxxxxxx>
> > On 1/26/26 17:28, Biju Das wrote:
> > >> For s2idle issue on RZ/G3L is DMA device is in asserted state, not
> > >> forwarding any IRQ to cpu for wakeup.
> > >>
> > >> For S2RAM issue on RZ/G3L is during suspend hardware turns DMAACLK
> > >> off/ Asserted state. Clock framwork is not turning On DMAACLK as it critical clk.
> > >>
> > >> Can you please check your TF-A for the second case? First case,
> > >> RZ/G3S may ok for reset assert state, it can forward IRQs to CPU.
> > >
> > > Just to summarize, currently there are 2 differences identified between RZ/G3S and RZ/G3L:
> > >
> > > SoC differences for s2idle:
> > >
> > > RZ/G3S: Can wake the system if the DMA device is in the assert state
> > >
> > > RZ/G3L: Cannot wake the system if the DMA device is in the assert state.
> > >
> > >
> > > TF-A differences for s2ram:
> > >
> > > RZ/G3S: TF_A turns on DMA_ACLK during boot/resume.
> > >
> > > RZ/G3L: TF_A does not handle DMA_ACLK during boot/resume.
> >
> > I'm seeing at [1] you are addressing these differences in the clock/reset drivers. With that, are you
> > still considering this patch is breaking your system?
>
> Still, thinking whether to add critical reset or go with SoC quirk in DMA driver.
> Some SoCs need DMA should be deasserted like critical clock
> that can be handled either
>
> 1) Add a simple SoC quirk in DMA driver
>
> Or
>
> 2) Implement critical reset in SoC specific clock driver and check for all resets.
>
> Is simple SoC quirk in DMA driver, something can be done for RZ/G2L family SoCs?

What if the DMA driver is not enabled?

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds