Re: [PATCH] arm64: dts: qcom: ipq8074: add SMEM support

[Bjorn Andersson <bjorn.andersson@linaro.org>]

On Wed 22 Sep 15:23 CDT 2021, Robert Marko wrote:

> On Tue, 21 Sept 2021 at 08:24, Kathiravan T <kathirav@codeaurora.org> wrote:
> >
> > On 2021-09-20 14:55, Robert Marko wrote:
> > > On Mon, 20 Sept 2021 at 04:52, Bjorn Andersson
> > > <bjorn.andersson@linaro.org> wrote:
> > >>
> > >> On Thu 02 Sep 16:47 CDT 2021, Robert Marko wrote:
> > >>
> > >> > IPQ8074 uses SMEM like other modern QCA SoC-s, so since its already
> > >> > supported by the kernel add the required DT nodes.
> > >> >
> > >> > Signed-off-by: Robert Marko <robimarko@gmail.com>
> > >>
> > >> Thanks for your patch Robert.
> > >>
> > >> > ---
> > >> >  arch/arm64/boot/dts/qcom/ipq8074.dtsi | 28 +++++++++++++++++++++++++++
> > >> >  1 file changed, 28 insertions(+)
> > >> >
> > >> > diff --git a/arch/arm64/boot/dts/qcom/ipq8074.dtsi b/arch/arm64/boot/dts/qcom/ipq8074.dtsi
> > >> > index a620ac0d0b19..83e9243046aa 100644
> > >> > --- a/arch/arm64/boot/dts/qcom/ipq8074.dtsi
> > >> > +++ b/arch/arm64/boot/dts/qcom/ipq8074.dtsi
> > >> > @@ -82,6 +82,29 @@ scm {
> > >> >               };
> > >> >       };
> > >> >
> > >> > +     reserved-memory {
> > >> > +             #address-cells = <2>;
> > >> > +             #size-cells = <2>;
> > >> > +             ranges;
> > >> > +
> > >> > +             smem_region: memory@4ab00000 {
> > >> > +                     no-map;
> > >> > +                     reg = <0x0 0x4ab00000 0x0 0x00100000>;
> > >> > +             };
> > >> > +     };
> > >> > +
> > >> > +     tcsr_mutex: hwlock {
> > >> > +             compatible = "qcom,tcsr-mutex";
> > >> > +             syscon = <&tcsr_mutex_regs 0 0x80>;
> > >>
> > >> Since it's not okay to have a lone "syscon" and I didn't think it was
> > >> worth coming up with a binding for the TCSR mutex "syscon" I rewrote
> > >> the
> > >> binding a while back. As such qcom,tcsr-mutex should now live in /soc
> > >> directly.
> > >>
> > >> So can you please respin accordingly?
> > >
> > > Sure, can you just confirm that the:
> > > reg = <0x01905000 0x8000>;
> > >
> > > Is the whole TCSR range as I don't have docs?
> >
> > Robert,
> >
> > TCSR_MUTEX block starts from 0x01905000 and has size 0x20000 (128KB)
> 
> Thanks, Kathiravan,
> TSCR mutex with MMIO reg under it works, but there is some weird probe
> ordering issue.
> 
> For whatever reason, SMEM will get probed only after MTD does and this
> will cause issues
> if SMEM parser is used as it will return -EPROBE_DEFER but the MTD
> core does not really
> handle it correctly and causes the device to reboot after failed parsing.
> 
> Now, I have no idea why does this variant which uses MMIO regmap probe
> so much later?
> 

Mani, do you have any input related to the probe deferral of the SMEM
partition parser, because SMEM not yet probed?

Thanks,
Bjorn