WNR3500L V1: no USB power using LEDE/openwrt

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foobar34
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WNR3500L V1: no USB power using LEDE/openwrt

I just installed LEDE on my WNR3500L V1. Everything works well, apart from the USB port. After many tests, I narrowed down the issue to LEDE code, not the router. USB works in the Netgear firmware, and USB is powered at boot.

I installed LEDE Reboot 17.01.4 r3560-79f57e422d / LuCI lede-17.01 branch (git-17.290.79498-d3f0685) over the Netgear firmware, and have not updated LEDE (since there’s no new build)

It looks as if during the boot process (very close to the end), the USB port gets powered down. I can measure the 5V on the USB port if I boot in failsafe mode, and during part of the boot process for the full LEDE boot. Towards the end, I can see 5V disappear.

I opened the router and I can see that there’s a dedicated power chip for the USB port. The enable pin for that chip is 3.3V while booting and when in failsafe mode. Towards the end of the boot process I can see the pin go to 0V, and the USB port is de-powered

I tried disabling wireless, but it makes no difference

Yesterday I tried playing with GPIOs (https://wiki.openwrt.org/doc/hardware/port.gpio), and created the gpiocontrol.sh shell file. I tried setting all existing GPIOs from 8 to 15 to high (1), saw that the USB power came up (yay!), started turning them off one by one, and GPIO 12 controls the USB power. I was able to turn it on and off a few times. I mounted a USB drive, everything worked. The only weird thing is that the setting persisted over reboots (i.e. all GPIOs were on, no matter what). Then, since I had seriously messed up my config over time ad to reset the other GPIOs, I stupidly decided to reset to factory settings the router.

After doing it (and recreating gpiocontrol.sh), I tried turning on GPIO 12, but nothing. No matter what I do, it always stays 0. Any pointer to why, on a clean system, I cannot turn on GPIO 12? It’s recognized and I can read it, but it always reads 0

Anyone using WNR3500L with openwrt and having USB power?

foobar34
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Final update: it is a NVRAM
Final update: it is a NVRAM configuration issue.
 
nvram set boardflags=0x00000710
nvram commit
 
followed by a power cycle (reboot is not enough). After that USB has power and everything works as expected
chrismor
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@foobar34

@foobar34

Hi I'm having a similar issue you had and I was just wondering how you found the nvram set boardflags?  I have found that I can turn on my usb port power by doing echo 1 > /sys/class/gpio/export