tjh.dev
USB: storage: Ignore driver CD mode for Realtek multi-mode Wi-Fi dongles
Many Realtek USB Wi-Fi dongles released in recent years have two modes:
one is driver CD mode which has Windows driver onboard, another one is
Wi-Fi mode. Add the US_FL_IGNORE_DEVICE quirk for these multi-mode devices.
Otherwise, usb_modeswitch may fail to switch them to Wi-Fi mode.
Currently there are only two USB IDs known to be used by these multi-mode
Wi-Fi dongles: 0bda:1a2b and 0bda:a192.
Information about Mercury MW310UH in /sys/kernel/debug/usb/devices.
T: Bus=02 Lev=01 Prnt=01 Port=01 Cnt=01 Dev#= 12 Spd=480 MxCh= 0
D: Ver= 2.00 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=64 #Cfgs= 1
P: Vendor=0bda ProdID=a192 Rev= 2.00
S: Manufacturer=Realtek
S: Product=DISK
C:* #Ifs= 1 Cfg#= 1 Atr=80 MxPwr=500mA
I:* If#= 0 Alt= 0 #EPs= 2 Cls=08(stor.) Sub=06 Prot=50 Driver=(none)
E: Ad=8a(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
E: Ad=0b(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms
Information about D-Link AX9U rev. A1 in /sys/kernel/debug/usb/devices.
T: Bus=03 Lev=01 Prnt=01 Port=02 Cnt=01 Dev#= 55 Spd=480 MxCh= 0
D: Ver= 2.00 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=64 #Cfgs= 1
P: Vendor=0bda ProdID=1a2b Rev= 0.00
S: Manufacturer=Realtek
S: Product=DISK
C:* #Ifs= 1 Cfg#= 1 Atr=e0 MxPwr=500mA
I:* If#= 0 Alt= 0 #EPs= 2 Cls=08(stor.) Sub=06 Prot=50 Driver=(none)
E: Ad=84(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
E: Ad=05(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms
Cc: stable <stable@kernel.org>
Signed-off-by: Zenm Chen <zenmchen@gmail.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/20250813162415.2630-1-zenmchen@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
authored by