Re: [PATCH v2 04/13] arm64: dts: qcom: sc7180: Remove reg-names property from LLCC node

Manivannan Sadhasivam
2022-12-13T17:17:01Z

On Tue, Dec 13, 2022 at 05:30:09PM +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 SC7180, 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@vger.kernel.org> # 5.6
>
> Oh, no, there is no single bug here. Binding from v5.6+ (which cannot be
> changed) required/defined such reg-names. This is neither a bug nor
> possible to backport.
>
> > Fixes: c831fa299996 ("arm64: dts: qcom: sc7180: Add Last level cache controller node")
>
> Drop.
>
> > Reported-by: Parikshit Pareek <quic_ppareek@quicinc.com>
> > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> > ---
> > arch/arm64/boot/dts/qcom/sc7180.dtsi | 1 -
> > 1 file changed, 1 deletion(-)
> >
> > diff --git a/arch/arm64/boot/dts/qcom/sc7180.dtsi b/arch/arm64/boot/dts/qcom/sc7180.dtsi
> > index f71cf21a8dd8..b0d524bbf051 100644
> > --- a/arch/arm64/boot/dts/qcom/sc7180.dtsi
> > +++ b/arch/arm64/boot/dts/qcom/sc7180.dtsi
> > @@ -2759,7 +2759,6 @@ dc_noc: interconnect@9160000 {
> > system-cache-controller@9200000 {
> > compatible = "qcom,sc7180-llcc";
> > reg = <0 0x09200000 0 0x50000>, <0 0x09600000 0 0x50000>;
> > - reg-names = "llcc_base", "llcc_broadcast_base";
>
> That's an ABI break...
>

As agreed, I will keep reg-names in dts for now.

Thanks,
Mani

> > interrupts = <GIC_SPI 582 IRQ_TYPE_LEVEL_HIGH>;
> > };
> >
>
> Best regards,
> Krzysztof
>

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