Hi,
The Lexar 3.0 USB mass storage on i.mx8mplus works sometimes with different behavior. Other USB devices like SanDisk, Samsung and Transcend works fine everytime. However Lexar 3.0 works sometimes in a particular scenarios like if we plug-in the USB device first and then boot the board, it works fine. But if we plug USB device after booting the board, it will get detected and work around 2 out of 10 times. The testing logs are attached here.
One difference is seen in MxPwr value for Lexar USB device and other devices. Logs are below for usb-devices command.
Lexar 3.0 USB
T: Bus=01 Lev=01 Prnt=01 Port=09 Cnt=01 Dev#= 41 Spd=480 MxCh= 0 D: Ver= 2.10 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=64 #Cfgs= 1 P: Vendor=05dc ProdID=a838 Rev=11.00 S: Manufacturer=Lexar S: Product=USB Flash Drive S: SerialNumber=AA14IYGKVI0QF18L C: #Ifs= 1 Cfg#= 1 Atr=80 MxPwr=500mA I: If#=0x0 Alt= 0 #EPs= 2 Cls=08(stor.) Sub=06 Prot=50 Driver=usb-storage
SanDisk USB
T: Bus=01 Lev=01 Prnt=01 Port=09 Cnt=01 Dev#= 42 Spd=480 MxCh= 0 D: Ver= 2.10 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=64 #Cfgs= 1 P: Vendor=0781 ProdID=5581 Rev=01.00 S: Manufacturer=SanDisk S: Product=Ultra S: SerialNumber=4C530001191203121182 C: #Ifs= 1 Cfg#= 1 Atr=80 MxPwr=224mA I: If#=0x0 Alt= 0 #EPs= 2 Cls=08(stor.) Sub=06 Prot=50 Driver=usb-storage
Transcend USB
T: Bus=02 Lev=01 Prnt=01 Port=04 Cnt=01 Dev#= 2 Spd=5000 MxCh= 0
D: Ver= 3.00 Cls=00(>ifc ) Sub=00 Prot=00 MxPS= 9 #Cfgs= 1
P: Vendor=8564 ProdID=1000 Rev=11.00
S: Manufacturer=JetFlash
S: Product=Mass Storage Device
S: SerialNumber=05CO5Z9ZYSBL9NDC
C: #Ifs= 1 Cfg#= 1 Atr=80 MxPwr=304mA
I: If#= 0 Alt= 0 #EPs= 2 Cls=08(stor.) Sub=06 Prot=50 Driver=usb-storage
Here the MxPwr value is highest for Lexar USB. This may be a clue for the problem.
Thanks,
Ansar Rasool