4.11 USB Host
This example demonstrates how to use USB host to mount mass stroage device and
verify the driver of USB host,to achieve the function of reading and writing USB flash
disk.
Hardware Preparation:
Hardware debugging environment to see chapter second.
USB flash disk
Board Type
MYD-AM335X
MYD-AM335X-Y
MYD-AM335X-J
USB Host interface
J3 or J4
J19
J27
Software Preparation:
Linux Kernel 4.1.18
mount and umount commands
Test Steps:
Plug the USB disk in the USB host interface of development board, use
mount
or
umount
command to load and unload USB disk. When users plug in the USB
disk, Linux kernel dumps the message as below:
# [ 334.568567] usb 2-1.4: new high-speed USB device number 3 using musb-hdrc
[ 334.688922] usb 2-1.4: New USB device found, idVendor=1908, idProduct=0226
[ 334.696305] usb 2-1.4: New USB device strings: Mfr=0, Product=0, SerialNumber=0
[ 334.743502] usb-storage 2-1.4:1.0: USB Mass Storage device detected
[ 334.751563] scsi host0: usb-storage 2-1.4:1.0
[ 334.762053] usbcore: registered new interface driver usb-storage
[ 334.788766] cpu cpu0: clk_voltdm_notifier_handler: Failed to scale voltage(1100000)
: -22
[ 334.797531] cpu cpu0: clk_voltdm_notifier_handler: Failed to scale voltage(950000):
-22
[ 334.806827] cpu cpu0: failed to set clock rate: -16
[ 334.812093] cpufreq: __target_index: Failed to change cpu frequency: -16
[ 335.759638] scsi 0:0:0:0: Direct-Access Generic Mass-Storage 1.11 PQ: 0 AN
SI: 2
[ 336.488565] sd 0:0:0:0: [sda] 15605760 512-byte logical blocks: (7.99 GB/7.44 GiB)
[ 336.497237] sd 0:0:0:0: [sda] Write Protect is off
[ 336.503459] sd 0:0:0:0: [sda] Mode Sense: 03 00 00 00
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