Hi Alan/Robert,
I've been working on extending your shuttle_usbat driver to support flash-based storage devices connected via the USBAT02 chip. I've got working code here and am nearly ready to submit this for inclusion, but there is one last problem that I'm trying to address.
The present-time shuttle_usbat driver supports hp8200 cd drives connected through a USBAT01 chip. Currently, my driver extension adds the USBAT02 USB ID into unusual_devs.h, and assumes that any device connected through the usbat02 chip is a flash-storage device.
This isn't ideal though. According to SCM, HP released some later revisions of the 8200 drive based on the USBAT02 chip. We also recieved a mail from an owner of one of these devices, so they definately exist. Also, SCM can neither confirm or deny that the HP8200 was the only user of the original USBAT.
( If you don't know, the only real difference between the USBAT and USBAT02 is
that the USBAT had a nasty bug where it doesn't work when connected through
certain USB hubs. That's fixed in USBAT02, and its also a simple rebranding:
SCM acquired shuttle at about this time, so most USBAT02's are branded as
SCM )
So, rather than assuming usbat=hp8200, usbat02=flash, we ideally want to be able to detect which device is being used during the initialization of the driver.
My question is, how can we do this?
With my USBAT02 flash devices, I have tried examining the device identification data returned from the ATAPI IDENTIFY DEVICE command (0xEC). Specifically, I've looked at word 0 (signature), words 10-19 (serial number), words 23-26 (firmware revision), and words 27-46 (model number).
Unfortunately, all of these fields appear to be media-dependant, and suprisingly only 1 of my 4 CF cards produces the CF signature defined in the CF specs (0x848A), there is definately no consistency here. (Plus, the driver should ideally support connection when no media is present.)
Any suggestions for other things I could try? Perhaps there is something unique to the HP8200 which would allow us to do e.g.:
if (some condition)
//device is hp8200
else
//device is flash
Thanks, Daniel
-------------------------------------------------------
SF email is sponsored by - The IT Product Guide
Read honest & candid reviews on hundreds of IT Products from real users.
Discover which products truly live up to the hype. Start reading now. http://productguide.itmanagersjournal.com/
_______________________________________________
linux-usb-devel@lists.sourceforge.net
To unsubscribe, use the last form field at:
https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
