When I attach pen-drive, I am seeing following logs. And when I remove pen-drive, file system does not unmount for 10-15 secs.
[ 35.183406] usb 1-1: new full-speed USB device number 2 using dwc_otg
[ 35.440812] usb 1-1: not running at top speed; connect to a high speed hub
[ 35.456740] usb 1-1: New USB device found, idVendor=0781, idProduct=5572
[ 35.479144] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[ 35.501552] usb 1-1: Product: Cruzer Switch
[ 35.513147] usb 1-1: Manufacturer: SanDisk
[ 35.535614] usb 1-1: SerialNumber: 4C532000050910112450
[ 35.571416] scsi0 : usb-storage 1-1:1.0
[ 36.619687] scsi 0:0:0:0: Direct-Access SanDisk Cruzer Switch 1.20 PQ: 0 ANSI: 5
[ 36.651795] sd 0:0:0:0: [sda] 3908352 512-byte logical blocks: (2.00 GB/1.86 GiB)
[ 36.682780] sd 0:0:0:0: [sda] Write Protect is off
[ 36.709971] sd 0:0:0:0: [sda] Write cache: disabled, read cache: enabled, doesn't support DPO or FUA
[ 36.756973] sda: sda1
Rahul B.