The Longmai Technologies USB Key (0x04b4:0xb708) advertises itself as a
SCSI/Bulk-only mass storage device but does not correctly handle ATA
pass-through commands. When such a command (ATA_12 or ATA_16) is sent to
the device it fails to respond and the transfer eventually times out,
leaving the device unusable.
Add an unusual_devs entry for this device that sets the US_FL_NO_ATA_1X
flag, so usb-storage short-circuits ATA pass-through commands and returns
INVALID COMMAND OPERATION CODE (0x20 0x05 0x24 0x00) instead of forwarding
them to the device.
Information about the device 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=06 Prot=50 MxPS=64 #Cfgs= 1
P: Vendor=04b4 ProdID=b708 Rev= 1.00
S: Manufacturer=Longmai Technologies
S: Product=USB Key
C:* #Ifs= 1 Cfg#= 1 Atr=80 MxPwr=100mA
I:* If#= 0 Alt= 0 #EPs= 2 Cls=08(stor.) Sub=06 Prot=50 Driver=usb-storage
E: Ad=81(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
E: Ad=02(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms
Reported-by: Ai Chao <aichao@kylinos.cn>
Cc: stable <stable@kernel.org>
Signed-off-by: Huang Wei <huangwei@kylinos.cn>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://patch.msgid.link/20260716033341.2830872-1-huangwei@kylinos.cn
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
USB_SC_DEVICE, USB_PR_CB, NULL,
US_FL_MAX_SECTORS_MIN),
+/* Reported by Ai Chao <aichao@kylinos.cn> */
+UNUSUAL_DEV( 0x04b4, 0xb708, 0x0000, 0xffff,
+ "Longmai Technologies",
+ "USB Key",
+ USB_SC_SCSI, USB_PR_BULK, NULL,
+ US_FL_NO_ATA_1X),
+
/*
* Reported by Simon Levitt <simon@whattf.com>
* This entry needs Sub and Proto fields