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Date:   Mon, 16 Jan 2023 19:57:13 -0600
From:   Bjorn Andersson <andersson@kernel.org>
To:     Konrad Dybcio <konrad.dybcio@linaro.org>
Cc:     Bjorn Andersson <quic_bjorande@quicinc.com>,
        Andy Gross <agross@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        linux-arm-msm@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, Johan Hovold <johan@kernel.org>
Subject: Re: [PATCH] arm64: dts: qcom: sc8280xp: Define CMA region for CRD
 and X13s
Message-ID: <20230117015713.j62qymja6bdbgxiu@builder.lan>
References: <20230113041025.4188910-1-quic_bjorande@quicinc.com>
 <c37bdea2-2154-975b-4ef3-570922944088@linaro.org>
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On Fri, Jan 13, 2023 at 03:17:05PM +0100, Konrad Dybcio wrote:
> 
> 
> On 13.01.2023 05:10, Bjorn Andersson wrote:
> > Booting the CRD needs roughly 64MB CMA, rather than relying on people
> > adding boot parameters etc define a region for this, to remove the
> > allocation errors from e.g. NVME.
> > 
> > While fixing the CRD define the same region for the X13s.
> > 
> > Signed-off-by: Bjorn Andersson <quic_bjorande@quicinc.com>
> > ---
> So, to reiterate, the NVMe needs ~64M of contiguous RAM for
> $reasons and without this patch, it is not guaranteed that
> it can always find such a block which causes issues and
> adding a CMA region resolves that, is that correct?
> 

That's correct, $reasons being that NVMe complains about failures to
allocate CMA memory. I'll post a v2 with this in the commit message.

Thanks,
Bjorn

> Konrad
> >  arch/arm64/boot/dts/qcom/sc8280xp-crd.dts                | 9 +++++++++
> >  .../boot/dts/qcom/sc8280xp-lenovo-thinkpad-x13s.dts      | 9 +++++++++
> >  2 files changed, 18 insertions(+)
> > 
> > diff --git a/arch/arm64/boot/dts/qcom/sc8280xp-crd.dts b/arch/arm64/boot/dts/qcom/sc8280xp-crd.dts
> > index b29c02307839..e30a37c73b90 100644
> > --- a/arch/arm64/boot/dts/qcom/sc8280xp-crd.dts
> > +++ b/arch/arm64/boot/dts/qcom/sc8280xp-crd.dts
> > @@ -128,6 +128,15 @@ vreg_wwan: regulator-wwan {
> >  
> >  		regulator-boot-on;
> >  	};
> > +
> > +	reserved-memory {
> > +		linux,cma {
> > +			compatible = "shared-dma-pool";
> > +			size = <0x0 0x8000000>;
> > +			reusable;
> > +			linux,cma-default;
> > +		};
> > +	};
> >  };
> >  
> >  &apps_rsc {
> > diff --git a/arch/arm64/boot/dts/qcom/sc8280xp-lenovo-thinkpad-x13s.dts b/arch/arm64/boot/dts/qcom/sc8280xp-lenovo-thinkpad-x13s.dts
> > index 78e61a8184c5..5bfd1f0b2a24 100644
> > --- a/arch/arm64/boot/dts/qcom/sc8280xp-lenovo-thinkpad-x13s.dts
> > +++ b/arch/arm64/boot/dts/qcom/sc8280xp-lenovo-thinkpad-x13s.dts
> > @@ -153,6 +153,15 @@ vreg_wwan: regulator-wwan {
> >  		regulator-boot-on;
> >  	};
> >  
> > +	reserved-memory {
> > +		linux,cma {
> > +			compatible = "shared-dma-pool";
> > +			size = <0x0 0x8000000>;
> > +			reusable;
> > +			linux,cma-default;
> > +		};
> > +	};
> > +
> >  	thermal-zones {
> >  		skin-temp-thermal {
> >  			polling-delay-passive = <250>;