Well, here's my list of what the 'popular OS' uses for all devices: INQUIRY (for only 36 bytes -- nothing else!) TEST_UNIT_READY REQUEST_SENSE ALLOW_MEDIUM_REMOVAL (mostly for eject purposes)
For disk-like media:
READ_10
WRITE_10
I'd have to go back to my notes for tape and CD media. But those aren't my
biggest problem areas -- the common probe and the disk driver are my
biggest headaches.
Note that MODE_SENSE isn't on this list. How does the 'popular OS' test
for write-protect, you ask? It tries to write and then looks for a
failure, AFAICT.
Note that this data comes from observations about what commands all devices
seem to support.
I'd be willing to write a helper, but I'm a bit out of my element here...
can someone at least suggest a good place to put such a helper (or
volunteer to mock one up for me)?
Matt
On Sun, Mar 23, 2003 at 07:39:01PM -0600, James Bottomley wrote:
> On Sun, 2003-03-23 at 19:37, Matthew Dharm wrote:
> > Actually, there is such a list. It's the commands that the 'popular OS'
> > uses, and I have a pretty good idea exactly what those are. That's why my
> > original approach was to just cut out the commands that fell outside that
> > definition.
>
> Well, if you want to write a helper for the mid layer that checks the
> commands and returns a Check Condition with sense Illegal Reguest on the
> bad ones, that sounds like the best approach. You can then call the
> helper function in the queuecommand of the problem emulated drivers.
>
> Can you publish a rough list of these?
>
> James
>
--
Matthew Dharm Home: [EMAIL PROTECTED]
Maintainer, Linux USB Mass Storage Driver
Dudes! May the Open Source be with you.
-- Eric S. Raymond
User Friendly, 12/3/1998
pgp00000.pgp
Description: PGP signature
