Re: [PATCH v2 11/13] arm64: dts: qcom: sm6350: Remove reg-names property from LLCC node

From: Manivannan Sadhasivam
Date: Tue Dec 13 2022 - 12:18:10 EST


On Tue, Dec 13, 2022 at 05:31:40PM +0100, Krzysztof Kozlowski wrote:
> On 12/12/2022 13:33, Manivannan Sadhasivam wrote:
> > The LLCC block has several banks each with a different base address
> > and holes in between. So it is not a correct approach to cover these
> > banks with a single offset/size. Instead, the individual bank's base
> > address needs to be specified in devicetree with the exact size.
> >
> > On SM6350, there is only one LLCC bank available. So only change needed is
> > to remove the reg-names property from LLCC node to conform to the binding.
> >
> > The driver is expected to parse the reg field based on index to get the
> > addresses of each LLCC banks.
> >
> > Cc: <stable@xxxxxxxxxxxxxxx> # 5.16
> > Fixes: ced2f0d75e13 ("arm64: dts: qcom: sm6350: Add LLCC node")
>
> This is a definitive no go. There is no bug here and such change cannot
> be backported.
>
> > Reported-by: Parikshit Pareek <quic_ppareek@xxxxxxxxxxx>
>
> What is the bug here which deserves a credit? reg-names in v5.16 were
> perfectly correct.
>

If the driver gets backported to v5.16, it won't. But anyway, this property
will stay in dts.

Thanks,
Mani

> > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
> > ---
> > arch/arm64/boot/dts/qcom/sm6350.dtsi | 1 -
> > 1 file changed, 1 deletion(-)
> >
> > diff --git a/arch/arm64/boot/dts/qcom/sm6350.dtsi b/arch/arm64/boot/dts/qcom/sm6350.dtsi
> > index 43324bf291c3..1f39627cd7c6 100644
> > --- a/arch/arm64/boot/dts/qcom/sm6350.dtsi
> > +++ b/arch/arm64/boot/dts/qcom/sm6350.dtsi
> > @@ -1174,7 +1174,6 @@ dc_noc: interconnect@9160000 {
> > system-cache-controller@9200000 {
> > compatible = "qcom,sm6350-llcc";
> > reg = <0 0x09200000 0 0x50000>, <0 0x09600000 0 0x50000>;
> > - reg-names = "llcc_base", "llcc_broadcast_base";
> > };
> >
> > gem_noc: interconnect@9680000 {
>
> Best regards,
> Krzysztof
>

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