Just type 'dmesg' in terminal. You also can redirect output of command to file: dmesg > dmesg.txt
257.943020] usb 5-2: new high-speed USB device number 4 using ehci-pci
[ 258.058915] usb 5-2: New USB device found, idVendor=0781, idProduct=74e5
[ 258.058919] usb 5-2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[ 258.058922] usb 5-2: Product: Rockbox media player
[ 258.058924] usb 5-2: Manufacturer: Rockbox.org
[ 258.058926] usb 5-2: SerialNumber: 1A8C5009705F11F2E00000000
[ 258.061708] usb-storage 5-2:1.0: USB Mass Storage device detected
[ 258.061786] scsi8 : usb-storage 5-2:1.0
[ 259.064557] scsi 8:0:0:0: Direct-Access Rockbox Internal Storage 0.00 PQ: 0 ANSI: 4
[ 259.066676] sd 8:0:0:0: [sdd] 7683072 512-byte logical blocks: (3.93 GB/3.66 GiB)
[ 259.067297] sd 8:0:0:0: [sdd] Write Protect is off
[ 259.067300] sd 8:0:0:0: [sdd] Mode Sense: 0b 00 00 08
[ 259.067918] sd 8:0:0:0: [sdd] No Caching mode page present
[ 259.067920] sd 8:0:0:0: [sdd] Assuming drive cache: write through
[ 259.070919] sd 8:0:0:0: [sdd] No Caching mode page present
[ 259.070922] sd 8:0:0:0: [sdd] Assuming drive cache: write through
[ 259.074174] sdd:
[ 259.077296] sd 8:0:0:0: [sdd] No Caching mode page present
[ 259.077300] sd 8:0:0:0: [sdd] Assuming drive cache: write through
[ 259.081420] sd 8:0:0:0: [sdd] Attached SCSI removable disk
[ 291.846021] usb 5-2: reset high-speed USB device number 4 using ehci-pci
[ 306.948028] usb 5-2: device descriptor read/64, error -110
[ 322.151021] usb 5-2: device descriptor read/64, error -110
[ 322.354020] usb 5-2: reset high-speed USB device number 4 using ehci-pci
[ 337.456018] usb 5-2: device descriptor read/64, error -110
[ 352.659021] usb 5-2: device descriptor read/64, error -110
[ 352.862025] usb 5-2: reset high-speed USB device number 4 using ehci-pci
[ 363.264019] usb 5-2: device not accepting address 4, error -110
[ 363.366023] usb 5-2: reset high-speed USB device number 4 using ehci-pci
[ 373.768498] usb 5-2: device not accepting address 4, error -110
[ 373.768526] usb 5-2: USB disconnect, device number 4
[ 373.768587] sd 8:0:0:0: Device offlined - not ready after error recovery
[ 373.873023] usb 5-2: new high-speed USB device number 5 using ehci-pci