[OpenWrt-Devel] Cleanup in 4.19 generic kernel config?

Daniel Engberg daniel.engberg.lists at pyret.net
Sat Feb 9 03:15:48 EST 2019


Hi,

After my attempt getting Linux 4.19 working for the Octeon target
I started to look at the generic configuration for 4.19 and it
seems that there are quite a bit of target specific options listed
and potentially generating larger kernels than necessary.
Given that some options are incorrect for certain targets I assume
that they get overridden and/or ignored. Unless I misunderstand
how the Linux kernel configuration works =y is equivalent to always
compiled into kernel?

I'm taking about this file by the way:
https://github.com/openwrt/openwrt/blob/master/target/linux/generic/config-4.19

Should be set by target? Shouldn't coexist with CONFIG_64BIT as
far as I can tell.
CONFIG_32BIT=y

ARM specific, should be set by target?
CONFIG_ARM_CPU_TOPOLOGY=y
CONFIG_ARM_DMA_MEM_BUFFERABLE=y
CONFIG_ARM_GIC_MAX_NR=1

Target specific, no need to have it enabled by default and/or
possibly at all?
CONFIG_ATA_BMDMA=y
CONFIG_ATA_SFF=y

Seems to be defined by default?
CONFIG_BLK_DEV_LOOP_MIN_COUNT=8
https://github.com/torvalds/linux/blob/master/drivers/block/Kconfig#L217

Should be set by target?
CONFIG_BOOKE_WDT_DEFAULT_TIMEOUT=3

Debug option - Adds unnecessary overhead?
CONFIG_BRANCH_PROFILE_NONE=y
https://cateee.net/lkddb/web-lkddb/BRANCH_PROFILE_NONE.html

Should be set by target (ARM)?
CONFIG_CACHE_L2X0_PMU=y

Should be set by target, why is it enabled in 2019?
CONFIG_CARDBUS=y

Should be set by target (seems x86/64x specific)?
CONFIG_DOUBLEFAULT=y

Gets defined automatically based on target/platform?
CONFIG_HZ=100
CONFIG_HZ_100=y

Already default?
CONFIG_IIO_CONSUMERS_PER_TRIGGER=2
https://cateee.net/lkddb/web-lkddb/IIO_CONSUMERS_PER_TRIGGER.html

Why?
CONFIG_ISDN=y
CONFIG_JOLIET=y

Should be set by target (ARM)?
CONFIG_KERNEL_MODE_NEON=y

Set Page_Size by target?
CONFIG_PAGE_SIZE_4KB=y
CONFIG_PPC_4K_PAGES=y

Already default?
CONFIG_PWRSEQ_EMMC=y
https://cateee.net/lkddb/web-lkddb/PWRSEQ_EMMC.html

Default 21 isn't enough?
CONFIG_RCU_CPU_STALL_TIMEOUT=60

Needed for?
CONFIG_RXKAD=y

Obsolete?
CONFIG_SLABINFO=y

Shouldn't be default and/or platform specific?
CONFIG_SND_X86=y

Needed for?
CONFIG_USB_ARMLINUX=y
CONFIG_USB_BELKIN=y

Platform specific?
CONFIG_USB_OHCI_LITTLE_ENDIAN=y

Platform specific?
CONFIG_X86_SYSFB=y

Best regads,
Daniel

_______________________________________________
openwrt-devel mailing list
openwrt-devel at lists.openwrt.org
https://lists.openwrt.org/mailman/listinfo/openwrt-devel



More information about the openwrt-devel mailing list