Re: [PATCH 10/11] ST SPEAr: Added default configuration files for SPEAr machines

From: Linus Walleij
Date: Thu Mar 11 2010 - 15:18:47 EST


2010/3/3 Viresh KUMAR <viresh.kumar@xxxxxx>:
> (...)
> +CONFIG_HAVE_GENERIC_DMA_COHERENT=y

Not specifically related to this defconfig because hundreds of defconfigs
use this, but HAVE_GENERIC_DMA_COHERENT is not used in anything but
a few Kconfig files, all just defining it. No single Makefile, #ifdef
or anything
else seems to be using this, so what is it for?? I can't find any use even if I
go back to kernel 2.6.11 on LXR.

> (...)
> +#
> +# Networking options
> +#
> +CONFIG_PACKET=y
> +CONFIG_PACKET_MMAP=y
> (...)

You're obviously doing a lot of networking in this system, but the machine
has no network interfaces defined... yet, I suppose, so if it's coming,
keep it. (Or are you running PPP over your UART?)

> +#
> +# Bluetooth device drivers
> +#
> +CONFIG_BT_HCIUART=m
> +CONFIG_BT_HCIUART_H4=y
> +CONFIG_BT_HCIUART_BCSP=y
> (...)

Same here, make sure you're really going to
have Bluetooth on this device.

> +#
> +# SCSI device support
> +#
> +# CONFIG_RAID_ATTRS is not set
> +CONFIG_SCSI=m
> +CONFIG_SCSI_DMA=y

Same issue here.

> +#
> +# Userland interfaces
> +#
> +CONFIG_INPUT_MOUSEDEV=y
> +# CONFIG_INPUT_MOUSEDEV_PSAUX is not set
> +CONFIG_INPUT_MOUSEDEV_SCREEN_X=1024
> +CONFIG_INPUT_MOUSEDEV_SCREEN_Y=768
> +CONFIG_INPUT_JOYDEV=m
> +CONFIG_INPUT_EVDEV=y
> +# CONFIG_INPUT_EVBUG is not set

...and here

> +CONFIG_INPUT_TOUCHSCREEN=y
> +# CONFIG_TOUCHSCREEN_AD7879 is not set
> +# CONFIG_TOUCHSCREEN_DYNAPRO is not set
> +# CONFIG_TOUCHSCREEN_FUJITSU is not set
> +CONFIG_TOUCHSCREEN_GUNZE=m

Aha OK where is that connected?

> +CONFIG_EXT3_FS=m

Good choice, nowadays I think you should even consider EXT4.
But you have no block device for it in the platform...
Again I guess it's a runner-up, just checking.

> +CONFIG_FS_POSIX_ACL=y

This is rarely used in embedded.

> +CONFIG_QUOTA=y

This is also rare in embedded.

> +#
> +# CD-ROM/DVD Filesystems
> +#
> (...)
> +#
> +# DOS/FAT/NT Filesystems
> +#

Again there is no corresponding block device for this.
(Just checkin.)

> +CONFIG_CRAMFS=m

Is cramfs really useful as a module?
Enlighten me.

> +CONFIG_NETWORK_FILESYSTEMS=y
> +CONFIG_NFS_FS=m
> +CONFIG_NFS_V3=y
> (...)

On what network interface?

> +#
> +# Partition Types
> +#
> +CONFIG_PARTITION_ADVANCED=y
> +# CONFIG_ACORN_PARTITION is not set
> +CONFIG_OSF_PARTITION=y
> +# CONFIG_AMIGA_PARTITION is not set
> +# CONFIG_ATARI_PARTITION is not set
> +CONFIG_MAC_PARTITION=y

I doubt that you need these weird partition types.

> +CONFIG_NLS=y
> +CONFIG_NLS_DEFAULT="utf8"
> +CONFIG_NLS_CODEPAGE_437=y

I usually only keep 437 but if you need the others, sure.

> +CONFIG_SECURITY_SELINUX=y

This is some serious stuff to compile into an embedded system,
make sure you really need it.

> +#
> +# Random Number Generation
> +#
> +CONFIG_CRYPTO_ANSI_CPRNG=m
> +CONFIG_CRYPTO_HW=y

Do you have crypto HW? It's not in the machine right now atleast.

Comments repeat for the other configs, I just wanna make sure you're
really gonna use all of this so that your kernel is not too big for no good
reason.

Yours,
Linus Walleij
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