linux-kernel - [PATCH 7/7] arm64: dts: qcom: sc7180: Use 'ranges' in arm,armv7-timer-mem node

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Date:   Thu, 12 Dec 2019 11:35:43 -0800
From:   Douglas Anderson <dianders@...omium.org>
To:     Andy Gross <agross@...nel.org>,
        Bjorn Andersson <bjorn.andersson@...aro.org>
Cc:     Vinod Koul <vkoul@...nel.org>, Kiran Gunda <kgunda@...eaurora.org>,
        Rajendra Nayak <rnayak@...eaurora.org>, swboyd@...omium.org,
        mka@...omium.org, Sandeep Maheswaram <sanm@...eaurora.org>,
        Amit Kucheria <amit.kucheria@...aro.org>,
        Maulik Shah <mkshah@...eaurora.org>,
        Douglas Anderson <dianders@...omium.org>,
        Taniya Das <tdas@...eaurora.org>,
        linux-arm-msm@...r.kernel.org, linux-kernel@...r.kernel.org,
        devicetree@...r.kernel.org, Rob Herring <robh+dt@...nel.org>,
        Mark Rutland <mark.rutland@....com>
Subject: [PATCH 7/7] arm64: dts: qcom: sc7180: Use 'ranges' in arm,armv7-timer-mem node

Running `make dtbs_check` yells:

  arch/arm64/boot/dts/qcom/sc7180-idp.dt.yaml: timer@...20000: #size-cells:0:0: 1 was expected

It appears that someone was trying to assert the fact that sub-nodes
describing frames would never have a size that's more than 32-bits
big.  That's certainly true in the case of sc7180.

I guess this is a hint that it's time to do the thing that nobody
seems to do but that "writing-bindings.txt" says we should all do.
Specifically it says: "DO use non-empty 'ranges' to limit the size of
child buses/devices".  That means we should probably limit the

I believe that this patch is the way to do it and there should be no
bad side effects here.  I believe that since we're far enough down
(not trying to describe an actual device, just some sub-pieces) that
this won't cause us to run into the problems that caused us to
increase the soc-level #address-cells and #size-cells to 2 in sdm845
in commit bede7d2dc8f3 ("arm64: dts: qcom: sdm845: Increase address
and size cells for soc").

I can at least confirm that "arch_mem_timer" seems to keep getting
interrupts in "/proc/interrupts" after this change.

Fixes: 90db71e48070 ("arm64: dts: sc7180: Add minimal dts/dtsi files for SC7180 soc")
Signed-off-by: Douglas Anderson <dianders@...omium.org>
---

 arch/arm64/boot/dts/qcom/sc7180.dtsi | 36 ++++++++++++++--------------
 1 file changed, 18 insertions(+), 18 deletions(-)

diff --git a/arch/arm64/boot/dts/qcom/sc7180.dtsi b/arch/arm64/boot/dts/qcom/sc7180.dtsi
index c671f0719d42..336cf65bdcc2 100644
--- a/arch/arm64/boot/dts/qcom/sc7180.dtsi
+++ b/arch/arm64/boot/dts/qcom/sc7180.dtsi
@@ -1206,59 +1206,59 @@ watchdog@...10000 {
 		};
 
 		timer@...20000{
-			#address-cells = <2>;
-			#size-cells = <2>;
-			ranges;
+			#address-cells = <1>;
+			#size-cells = <1>;
+			ranges = <0 0 0x17c21000 0x10000>;
 			compatible = "arm,armv7-timer-mem";
 			reg = <0 0x17c20000 0 0x1000>;
 
-			frame@...21000 {
+			frame@0 {
 				frame-number = <0>;
 				interrupts = <GIC_SPI 8 IRQ_TYPE_LEVEL_HIGH>,
 					     <GIC_SPI 6 IRQ_TYPE_LEVEL_HIGH>;
-				reg = <0 0x17c21000 0 0x1000>,
-				      <0 0x17c22000 0 0x1000>;
+				reg = <0x0000 0x1000>,
+				      <0x1000 0x1000>;
 			};
 
-			frame@...23000 {
+			frame@...0 {
 				frame-number = <1>;
 				interrupts = <GIC_SPI 9 IRQ_TYPE_LEVEL_HIGH>;
-				reg = <0 0x17c23000 0 0x1000>;
+				reg = <0x2000 0x1000>;
 				status = "disabled";
 			};
 
-			frame@...25000 {
+			frame@...0 {
 				frame-number = <2>;
 				interrupts = <GIC_SPI 10 IRQ_TYPE_LEVEL_HIGH>;
-				reg = <0 0x17c25000 0 0x1000>;
+				reg = <0x4000 0x1000>;
 				status = "disabled";
 			};
 
-			frame@...27000 {
+			frame@...0 {
 				frame-number = <3>;
 				interrupts = <GIC_SPI 11 IRQ_TYPE_LEVEL_HIGH>;
-				reg = <0 0x17c27000 0 0x1000>;
+				reg = <0x6000 0x1000>;
 				status = "disabled";
 			};
 
-			frame@...29000 {
+			frame@...0 {
 				frame-number = <4>;
 				interrupts = <GIC_SPI 12 IRQ_TYPE_LEVEL_HIGH>;
-				reg = <0 0x17c29000 0 0x1000>;
+				reg = <0x8000 0x1000>;
 				status = "disabled";
 			};
 
-			frame@...2b000 {
+			frame@...0 {
 				frame-number = <5>;
 				interrupts = <GIC_SPI 13 IRQ_TYPE_LEVEL_HIGH>;
-				reg = <0 0x17c2b000 0 0x1000>;
+				reg = <0xa000 0x1000>;
 				status = "disabled";
 			};
 
-			frame@...2d000 {
+			frame@...0 {
 				frame-number = <6>;
 				interrupts = <GIC_SPI 14 IRQ_TYPE_LEVEL_HIGH>;
-				reg = <0 0x17c2d000 0 0x1000>;
+				reg = <0xc000 0x1000>;
 				status = "disabled";
 			};
 		};
-- 
2.24.1.735.g03f4e72817-goog