4G LTE dongle not switch mode on Raspberry Pi

Installing and Using OpenWrt
1

I have a random branded 4G LTE dongle, Vendor 05c6, ProdID F000.

IMG_20240217_004227617
IMG_20240217_0042276171920×1440 155 KB

When working with openwrt 22.03, it doesn't switch mode:

IMG_20240216_203516789~2
IMG_20240216_203516789~21920×1143 214 KB

After usb-switchmode, its ProdID doesn't change to 6000, and no ttyUSB is created.

It's working fine with Raspios 11:

IMG_20240217_004213937~2
IMG_20240217_004213937~21920×1129 325 KB

2

Compared the two modswitches ?

Did you search the forum for 05c6:6000 ?

3

Hi Frollic,

Thanks for your advice.

I searched the forum for 05c6:6000 and all are about the lucky guys who have their dongles switched successfully, while mine stuck in 05c6:f000 even after usb-modeswitch is installed.

I then searched for 05c6:f000, and finally came to one post that gives an example file that is working for his modem: [SOLVED] 3g/LTE modem (Qualcomm MDM9200) - USB modeswitch problem - #7 by ketyosz

{

	"messages": [

		"5553424308306384c000000080000671030000000000000000000000000000"

	],

	"devices": {

		"05c6:f000": {

			"*": {

				"t_vendor": "05c6",

				"t_product": "6000",

				"msg": [0]

			}

		}

	}

}

But I wonder if that magic will work for me, because a similar logic can already be found in the /etc/usb-mode.json:

$ grep 05c6:f000 -A10 build_dir/target-aarch64_cortex-a53_glibc/root-bcm27xx/etc/usb-mode.json
                "05c6:f000": {
                        "*": {
                                "t_vendor": 1478,
                                "t_product": [ 22, 24576, 36864 ],
                                "mode": "StandardEject",
                                "msg": [ 11 ]
                        }
                },
                "05c7:1000": {
                        "*": {
                                "t_vendor": 1479,
4

Create a restore point, and try it.

The worst thing that will happen is it does not work and you can restore back to the same situation.

You could also ask the Raspberry support forum if they have any idea why it works with their OS but not OpenWrt.

5

Disable usb_modeswitch from running automatically, reboot.
Create a custom .json file and run the program manually as shown in https://openwrt.org/docs/guide-user/network/wan/wwan/usb-modeswitching
Observe the output, hopefully it will be something useful there. Please do not use pictures to show text.
It looks like it has only serial interfaces and no QMI/MBIM/etc. Is it worth spending time on this?

8

Hi guys,
Miracle happened. The example file switches my modem perfectly!

[screenshot omitted]

After some trial and error, I found the cause in /etc/usb-mode.json:

"mode": "StandardEject",

Comment out this line and usb-modeswitch works. Is this a bug or it is just my modem that behaves strangely?