I have TP-LINK TL-WR841ND wireless router. Its chip supports USB, however,
TL-WR841ND does not have a physical USB port (although its possible to add through a hardware mod, only a few people have done it)

For all the routers with this chip, USB_SUPPORT (and AUDIO_SUPPORT, which depends on USB_SUPPORT) - are enabled and hardcoded in target/Config.in file. They can't be disabled through "make menuconfig", the only way to disable them is by manually editing target/Config.in to comment these lines:

# config AUDIO_SUPPORT <--- commented both lines
#        bool <--- commented both lines

config PCI_SUPPORT
# select AUDIO_SUPPORT <--- only this line is commented
bool

# config USB_SUPPORT <--- all three lines are commented
#        select AUDIO_SUPPORT <--- all three lines are commented
#        bool <--- all three lines are commented

Why this is a problem? TL-WR841ND has a small flash chip - just 4MB, quite hard to fit all the good stuff there. By disabling the unnecessary USB_SUPPORT and AUDIO_SUPPORT options, for a device which does not have USB port (without a hardware mod), I save about 100-150 KB which is HUGE ! Probably some people who has another router with USB port, but dont use this port, would want to disable these options to save space

dear OpenWRT developer, please:
1) Make it possible to enable/disable these options from menuconfig
2) Disable these options by default for the routers without a hardware USB port (like TL-WR841ND), but let them to be enabled just in case someone has done a hardware mod

P.S. posting this ticket here because the official place for OpenWRT tickets does not allow a registration for new users (Trac anti-spam system bans you even if you successfully enter the captcha code!)

(Last edited by mward15 on 8 Jan 2017, 13:14)

Delete .config (don't forget to make a backup first, in necessary).

Run make menuconfig and select the Target System (Atheros AR7xxx/AR9xxx) and the target Profile for your router and save and exit. Run make defconfig and make menuconfig again.

When I do this, nothing is selected, even while CONFIG_AUDIO_SUPPORT=Y in .config. I would not edit the Config.in files, if I were you; you might break something.

If you cannot disable an option in menuconfig, it's probably because you have selected something else that depends on that option. Select < Help > in menuconfig when on that option and you can see what it selects and by what it is selected.

(Last edited by maartenjd on 8 Jan 2017, 18:07)

It's because selecting that platform probably enables USB_SUPPORT=y or something similar.

You can always hit ? in the buildroot when your cursor sits on the symbol in question (in make menuconfig). THat will show you what needs or enables it, so you can do a more targeted search.

It does just that.
https://github.com/openwrt/openwrt/blob … g-4.4#L425
CONFIG_USB_SUPPORT=y

Deleting that line is the "correct" (or easy) way to disable USB support.

I'm also interested in this.  My Trendnet TEW732BR v1.x board is reported to have a usb pin holes that are unpopulated with the actual usb socket.  I'm a little less compulsive, compared to the OP, about the flash/ram as the TEW732BR has 8mb flash and 64mb ram.  Still, I think the purpose of the project is to be able to tailor the firmware to the hardware - one size does not always fit all.

As an aside, If one were to attempt to optimize an AR71xx build for the TEW732BR, what is the recommended Build Platform - I mainly use OpenBSD.  My favorite Linux is Debian but my attempts with the build script in Debian amd64 Testing segfaulted.

(Last edited by shep on 9 Jan 2017, 04:11)