difos/target/linux/bcm27xx/patches-6.12/950-0417-arm64-Kconfig-Don-t-set-DMA_BOUNCE_UNALIGNED_KMALLOC.patch
Álvaro Fernández Rojas 8f9e91ad03 bcm27xx: add 6.12 patches from RPi repo
These patches were generated from:
https://github.com/raspberrypi/linux/commits/rpi-6.12.y
With the following command:
git format-patch -N v6.12.27..HEAD
(HEAD -> 8d3206ee456a5ecdf9ddbfd8e5e231e4f0cd716e)

Exceptions:
- (def)configs patches
- github workflows patches
- applied & reverted patches
- readme patches
- wireless patches

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
2025-05-21 11:32:18 +02:00

29 lines
1 KiB
Diff

From ccba125f1d9f66aa51fedfd1a0b13d1d38cc33c1 Mon Sep 17 00:00:00 2001
From: Phil Elwell <phil@raspberrypi.com>
Date: Wed, 21 Feb 2024 14:16:21 +0000
Subject: [PATCH] arm64/Kconfig: Don't set DMA_BOUNCE_UNALIGNED_KMALLOC
If enabled, DMA_BOUNCE_UNALIGNED_KMALLOC causes the swiotlb buffers
(64MB, by default) to be allocated, even on systems where the DMA
controller can reach all of RAM. This is a huge amount of RAM to
waste on a device with only 512MB to start with, such as the Zero 2 W.
See: https://github.com/raspberrypi/linux/issues/5975
Signed-off-by: Phil Elwell <phil@raspberrypi.com>
---
arch/arm64/Kconfig | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -130,7 +130,8 @@ config ARM64
select CRC32
select DCACHE_WORD_ACCESS
select DYNAMIC_FTRACE if FUNCTION_TRACER
- select DMA_BOUNCE_UNALIGNED_KMALLOC
+ # Disable this to save 64MB when DMA controllers can reach all of RAM
+ # select DMA_BOUNCE_UNALIGNED_KMALLOC
select DMA_DIRECT_REMAP
select EDAC_SUPPORT
select FRAME_POINTER