Bug 211497

Summary:	mwifiex - missing usb ID/support for 88W8786U (1286:203c) in mwifiex_usb
Product:	Networking	Reporter:	mwifiex88w8786u (mwifiex88w8786u)
Component:	Wireless	Assignee:	networking_wireless (networking_wireless)
Status:	NEW ---
Severity:	blocking	CC:	justincase
Priority:	P1
Hardware:	All
OS:	Linux
Kernel Version:	5.9	Subsystem:
Regression:	No	Bisected commit-id:

Description mwifiex88w8786u 2021-01-31 11:34:05 UTC

The driver is listed to support the 88W8786U USB Wifi Adapter. But when attaching it, the kernel module does not load automaticly.

I tried: bash -c "echo 1286 203c > /sys/bus/usb/drivers/mwifiex_usb/new_id" and manually loading the driver.

The kernel output was: 
[ 3134.156360] mwifiex_usb: unknown id_product 0x203c
[ 3134.217742] usb 2-1.2: firmware: direct-loading firmware mrvl/usb8797_uapsta.bin
[ 3134.218280] usb 2-1.2: start to download FW...
[ 3135.652643] usb 2-1.2: info: FW download over, size 553940 bytes
[ 3135.652650] usb 2-1.2: info: _mwifiex_fw_dpc: unregister device

The device is listed here:

https://wikidevi.wi-cat.ru/Mwifiex
Quote: Marvell (Avastar) 88W8797 (88W8786U [1286:203c]) - mwifiex - a/b/g/n - USB 

lsusb with kernel 5.9:
Bus 002 Device 007: ID 1286:203c Marvell Semiconductor, Inc. K30326 802.11bgn Wireless Module [Marvell 88W8786U]

Please add the missing IDs to support the device.
Thanks

Comment 1 mwifiex88w8786u 2021-02-01 09:11:38 UTC

To fix all the unclear parts(thanks to PaulFertser in IRC to mention that my bugreport is not fully clear):
I tried it on a second, completely different linux distro with kernel 5.4:
How i tested it:

1. Boot up live linux iso
2. sudo modprobe mwifiex_usb
3. sudo bash -c "echo 1286 203c > /sys/bus/usb/drivers/mwifiex_usb/new_id"

Then i attached the usb device.
The complete relevant output looks like this:

[ 4861.417536] usbcore: registered new interface driver mwifiex_usb
[ 4885.702458] usb 2-1.2: new high-speed USB device number 5 using ehci-pci
[ 4885.813859] usb 2-1.2: New USB device found, idVendor=1286, idProduct=203c, bcdDevice=31.14
[ 4885.813867] usb 2-1.2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[ 4885.813871] usb 2-1.2: Product: Marvell Wireless Device
[ 4885.813874] usb 2-1.2: Manufacturer: Marvell
[ 4885.813878] usb 2-1.2: SerialNumber: 0000000000000000
[ 4885.818701] mwifiex_usb: unknown id_product 0x203c
[ 4885.848597] usb 2-1.2: start to download FW...
[ 4887.286318] usb 2-1.2: info: FW download over, size 553940 bytes
[ 4887.286328] usb 2-1.2: info: _mwifiex_fw_dpc: unregister device

Comment 2 mwifiex88w8786u 2021-02-01 09:44:12 UTC

Because the Marvell own developers have not added anything new to the mwifiex driver since 2018 https://git.kernel.org/pub/scm/linux/kernel/git/kvalo/wireless-drivers-next.git/log/drivers/net/wireless/marvell/mwifiex/usb.c
thanks to PaulFertser this is the things i have to be done next:

1. Get a windows machine to install the windows driver on it
2. Read out the PID for the wifi device
3. Add the PID for the wifi device to the usb.c file from the mwifiex driver
4. Build a new mwifiex driver module and test that out if its working
5. When its working i have to ask again how to create a commit for this driver

side note: This additional work with building a custom driver module is required, because at the mwifiex driver it is not enough to just add the missing usb id to usb_id like i did. There seems to be no ability to add such a required PID to the linux driver without building it with the modified usb.c file.


This is also a important information from PaulFertser for this driver that should not be lost:

Quote: btw, that line in the wiki (https://wikidevi.wi-cat.ru/Mwifiex) saying your device is equivalent to 8797 might be untrue. Reading the code suggests me unknown devices added via new_id are treated in the same way 8797 is, and since it doesn't work probably your device is just different enough.

Comment 3 Yill Din 2022-01-26 12:24:36 UTC

On https://unix.stackexchange.com/q/683559 there is also a few of us trying to sort out this issue.
Can anyone explain how you got step 1 to succeed?
1. Get a windows machine to install the windows driver on it
Both a W7 standard installation and a W10 virtual machine were unable to find the appropriate drivers for the device. Though it is properly recognized at the hardware level (brought to 3.3V with an LM317) it seems impossible to get any further.