Re: [PATCH] definitive abstraction of the mode_sense commands

[Matthew Dharm <mdharm-scsi@one-eyed-alien.net>]

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On Tue, Jun 24, 2003 at 06:10:29PM +1000, Douglas Gilbert wrote:
> For really depraved devices it can be useful to send a
> MODE SENSE(6 or 10) that only asks for a 4 byte response. From
> this response the length of the respone that can be supplied
> is deduced. Then a second MODE SENSE can be
> issued for the now known response length. Yes, it's
> horrible, but that is precisely what Joerg Schilling
> does in cdrecord.
> Your code seems to have this technique in mind but requires
> a MODE SENSE(10) response buffer to be at least 8 bytes long.

The code does it this way because more devices seem to work that way.  That
is, always ask for the 'header' size as a minimum, and header size depends
on which command you send.

Lots of devices can't return less than the header size.

Matt

-- 
Matthew Dharm                              Home: mdharm-usb@one-eyed-alien.net 
Maintainer, Linux USB Mass Storage Driver

What, are you one of those Microsoft-bashing Linux freaks?
					-- Customer to Greg
User Friendly, 2/10/1999

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