Re: [usb-storage] Re: [PATCH] fix Sony USB mass storage - pass larger receive buffer

Pat LaVarre
2003-11-13T16:22:16Z

> > I'm starting to think that this may be the best solution --
> > blacklist all MODE_SENSE[_10] commands from all Direct-Access
> > devices.
>
> I was just going to suggest that myself -- or rather, blacklist all
> MODE-SENSE(x) commands from all USB disk-type devices.

We may as well fix SCSI over IDE and SCSI over 1394/FireWire/iLink at
the same time we fix SCSI over USB, yes?

> Is there any strong reason not to do this?

Have we yet begun to experiment with disks that we can write protect?

> Bear in mind that Windows apparently does not use these commands.

Rather, Windows either does not use the variations in these commands
that we have tried or else uses a different variation of reset that
works.

We could blacklist just USB MSC CBI/CB, for example, thus fixing the
Sony without making connections, especially SG_IO connections, to USB
MSC BBB more opaque.

> I don't see how not knowing the true read-write status or caching type
> will hurt anything.

Anybody know why Jens Axboe so vehemently rejected my suggestion that
that we teach cdrom.ko and sr_mod.ko to pass writes thru to all PDT x05
DVD/CD?

> (And the read-write status can be adjusted, if necessary, when a WRITE
> command fails with Medium Error: Write Protected sense.)

Aye. But will the layers above cope well with such a late error? I've
seen dmesg spew when playing with mounting udf.ko writable on top of a
read-only disc.

Pat LaVarre