[PATCH] arm64: dts: broadcom: Fix L2 linesize for Raspberry Pi 5

From: Willow Cunningham
Date: Thu Oct 10 2024 - 11:08:51 EST


From: Willow Cunningham <willow.e.cunningham@xxxxxxxxx>

Fixes: faa3381267d0 ("arm64: dts: broadcom: Add minimal support for
Raspberry Pi 5")

Set the cache-line-size parameter of the L2 cache for each core to the
correct value of 64 bytes.

Previously, the L2 cache line size was incorrectly set to 128 bytes
for the Broadcom BCM2712. This causes validation tests for the
Performance Application Programming Interface (PAPI) tool to fail as
they depend on sysfs accurately reporting cache line sizes.

The correct value of 64 bytes is stated in the official documentation of
the ARM Cortex A-72, which is linked in the comments of
arm64/boot/dts/broadcom/bcm2712.dtsi as the source for cache-line-size.

Signed-off-by: Willow Cunningham <willow.e.cunningham@xxxxxxxxx>
---
arch/arm64/boot/dts/broadcom/bcm2712.dtsi | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/arm64/boot/dts/broadcom/bcm2712.dtsi b/arch/arm64/boot/dts/broadcom/bcm2712.dtsi
index 6e5a984c1d4e..26a29e5e5078 100644
--- a/arch/arm64/boot/dts/broadcom/bcm2712.dtsi
+++ b/arch/arm64/boot/dts/broadcom/bcm2712.dtsi
@@ -67,7 +67,7 @@ cpu0: cpu@0 {
l2_cache_l0: l2-cache-l0 {
compatible = "cache";
cache-size = <0x80000>;
- cache-line-size = <128>;
+ cache-line-size = <64>;
cache-sets = <1024>; //512KiB(size)/64(line-size)=8192ways/8-way set
cache-level = <2>;
cache-unified;
@@ -91,7 +91,7 @@ cpu1: cpu@1 {
l2_cache_l1: l2-cache-l1 {
compatible = "cache";
cache-size = <0x80000>;
- cache-line-size = <128>;
+ cache-line-size = <64>;
cache-sets = <1024>; //512KiB(size)/64(line-size)=8192ways/8-way set
cache-level = <2>;
cache-unified;
@@ -115,7 +115,7 @@ cpu2: cpu@2 {
l2_cache_l2: l2-cache-l2 {
compatible = "cache";
cache-size = <0x80000>;
- cache-line-size = <128>;
+ cache-line-size = <64>;
cache-sets = <1024>; //512KiB(size)/64(line-size)=8192ways/8-way set
cache-level = <2>;
cache-unified;
@@ -139,7 +139,7 @@ cpu3: cpu@3 {
l2_cache_l3: l2-cache-l3 {
compatible = "cache";
cache-size = <0x80000>;
- cache-line-size = <128>;
+ cache-line-size = <64>;
cache-sets = <1024>; //512KiB(size)/64(line-size)=8192ways/8-way set
cache-level = <2>;
cache-unified;
--
2.39.2