On Wed, Jan 09, 2008 at 10:44:49PM +0100, Hans de Goede wrote: > First of all sorry for the somewhat massive cross-posting, I've spend a > significant amount of time hunting down this bug, and so far the response > has been less the overwhelming. > The cardreader of the multi function printers will "crash" and from that > moment on no longer communicate in any sane way, if you try to read the > last sector of an sdcard* in a read that is more then 1 sector, so trying > to read 8 sectors starting at sector capicity-8 will crash it, as will > reading 2 sectors starting at sector capicity-2, however reading the last > sector in a one 1 sector read will succeed! (* xdcards seem to be fine). To continue the history on this.... we over in usb-storage land looked at this and think it belongs in the SCSI layer. We don't like changing commands in-flight; it has, historically, caused us all sorts of issues in the past. Furthermore, this seems like the likely sort of off-by-one bug that can affect many types of devices, not just USB. I'd really like to see this in sd_mod -- I have no objection to requiring an HCD to set a flag to indicate that it should be used, if really desired. But, it seems to me to be a much easier change to make where the command originated rather than in mid-flight. Matt -- Matthew Dharm Home: mdharm-usb@xxxxxxxxxxxxxxxxxx Maintainer, Linux USB Mass Storage Driver P: Nine more messages in admin.policy. M: I know, I'm typing as fast as I can! -- Pitr and Mike User Friendly, 11/27/97
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