Hi,
I have decided that it is time to buy a USB3 stick for live system
(rescue) that boots fast enough. To my surprise I can boot kernel and
initrd, but not live system. Kernel identifies the USB stick as another
product and does not recognize the existing partition from which the
kernel is loaded.
Does anybody has any idea what changes between UEFI (or grub) and Linux
kernel and how to switch device state when Linux is running (without
unplugging the pen drive)?
Usually the device as recognized as (ignore discrepancy in bus and port
numbers, they are from notes taken at different moments on 2 laptops)
usb 3-3: Product: Mass Storage Device
usb 3-3: Manufacturer: JetFlash
lsusb -vt
/: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/2p, 10000M
ID 1d6b:0003 Linux Foundation 3.0 root hub
|__ Port 2: Dev 5, If 0, Class=Mass Storage, Driver=usb-storage, 5000M
ID 8564:1000 Transcend Information, Inc. JetFlash
however it may accidentally become
usb 3-3: Product: SM3265AB MEMORY BAR
usb 3-3: Manufacturer: Silicon Motion,Inc.
|__ Port 3: Dev 8, If 0, Class=Mass Storage, Driver=usb-storage, 480M
ID 090c:3265 Silicon Motion, Inc. - Taiwan (formerly Feiya
Technology Corp.)
If the computer is rebooted from this state then it is not recognized by
UEFI and Linux kernel any more
usb 3-1: Device not responding to setup address.
usb 3-1: device not accepting address 2, error -71
usb usb3-port1: attempt power cycle
...
usb 3-1: device not accepting address 5, error -71
usb usb3-port1: unable to enumerate USB device
and unplugging is required to recover from a broken state.
f3write & f3read work almost perfectly. I saw switching from Transcend
to Silicon Motion while f3read was running, but next time (after
unplug/plug cycle) it completed successfully.
It seems, attempt of booting live system is a reliable way to put the
device into its "Silicon Motion" state. It is not a power limit issue, I
tried to connect the stick through a powered USB3 hub.
I have tried the following commands, put the pen drive remains "Transcend"
usbreset 8564:1000
echo 0 > /sys/bus/usb/devices/3-1/authorized
echo 1 > /sys/bus/usb/devices/3-1/authorized
echo 0000:00:14.0 >/sys/bus/pci/drivers/xhci_hcd/unbind
echo 0000:00:14.0 >/sys/bus/pci/drivers/xhci_hcd/bind
What I cat try to simplify boot from the USB scenario?
I blame either pen drive USB controller or its firmware. On the other
hand, if boot is not involved then device works almost perfectly
(besides it is a cheap and so a rather slow drive). If the stick is
plugged before power on and the laptop is booted from the internal drive
then kernel properly recognizes the USB stick. I can not figure out what
may happen due to access by UEFI or grub.
