U3GINIT_SCSIEJECT quirk

[Don Lewis]

On 15 Nov, Hans Petter Selasky wrote:
> On 11/15/13 00:37, Don Lewis wrote:
>> My first question is how does U3GINIT_SCSIEJECT manage to ever work?  It
>> seems like there would be chicken vs. egg issue here.  The quirk is on
>> the u3g device, so how would it get activated until the u3g device is
>> attached?  The u3g device doesn't appear until the umass device is
>> ejected.
> 
> Hi,
> 
> Check the VID and PID of your USB device using usbconfig. Maybe it is 
> not the same value in both cases?

I don't know how the device would know if it's being the first time
after a reboot, but anyway:

reboot

ugen2.2: <Novatel Wireless CDMA Novatel Wireless Inc.> at usbus2, cfg=0 md=HOST spd=FULL (12Mbps) pwr=ON (500mA)

  bLength = 0x0012 
  bDescriptorType = 0x0001 
  bcdUSB = 0x0110 
  bDeviceClass = 0x0000 
  bDeviceSubClass = 0x0000 
  bDeviceProtocol = 0x0000 
  bMaxPacketSize0 = 0x0040 
  idVendor = 0x1410 
  idProduct = 0x5020 
  bcdDevice = 0x0000 
  iManufacturer = 0x0001  <Novatel Wireless Inc.>
  iProduct = 0x0002  <Novatel Wireless CDMA >
  iSerialNumber = 0x0004  <091166643730000>
  bNumConfigurations = 0x0001 

camcontrol eject

ugen2.2: <Novatel Wireless CDMA Novatel Wireless Inc.> at usbus2, cfg=0 md=HOST spd=FULL (12Mbps) pwr=ON (500mA)

  bLength = 0x0012 
  bDescriptorType = 0x0001 
  bcdUSB = 0x0110 
  bDeviceClass = 0x0000 
  bDeviceSubClass = 0x0000 
  bDeviceProtocol = 0x0000 
  bMaxPacketSize0 = 0x0040 
  idVendor = 0x1410 
  idProduct = 0x5020 
  bcdDevice = 0x0000 
  iManufacturer = 0x0001  <Novatel Wireless Inc.>
  iProduct = 0x0002  <Novatel Wireless CDMA >
  iSerialNumber = 0x0004  <091166643730000>
  bNumConfigurations = 0x0001 

unplug, power off, replug

ugen2.2: <Novatel Wireless CDMA Novatel Wireless Inc.> at usbus2, cfg=0 md=HOST spd=FULL (12Mbps) pwr=ON (500mA)

  bLength = 0x0012 
  bDescriptorType = 0x0001 
  bcdUSB = 0x0110 
  bDeviceClass = 0x0000 
  bDeviceSubClass = 0x0000 
  bDeviceProtocol = 0x0000 
  bMaxPacketSize0 = 0x0040 
  idVendor = 0x1410 
  idProduct = 0x6000 
  bcdDevice = 0x0000 
  iManufacturer = 0x0001  <Novatel Wireless Inc.>
  iProduct = 0x0002  <Novatel Wireless CDMA >
  iSerialNumber = 0x0004  <091166643731000>
  bNumConfigurations = 0x0001 

Hmn, interesting ... idProduct is now 0x6000.   Even stranger is that it
worked with the quirk I added for 0x5020!!!

> U3G patch looks OK.
> 
> The SCSI quirk is not needed. This should be fixed in the SCSI stack!

I don't have any problems on my unpatched 8.4-STABLE laptop, but I do on
11-CURRENT.  It seems sort of odd that the device would be getting a
PREVENT/ALLOW MEDIUM REMOVAL command right after it is attached (maybe
from geom tasting it?), but without the UQ_MSC_NO_PREVENT_ALLOW quirk, I
get a bunch of SCSI read errors as mentioned here:
<http://docs.FreeBSD.org/cgi/mid.cgi?201311140129.rAE1TQnm070352>.
That seems to but CAM into a bad state that causes a use after free
issue the triggers a panic when the umass device goes away.  That seems
like a definite bug.  I suspect that it might be related to the recent
batch of CAM changes.  In any case, the quirk also seems to prevent the
panic.