On Fri, 20 Feb 2009, Mike Lampard wrote: > On Fri, 20 Feb 2009 05:17:42 pm Mike Lampard wrote: > > Hi All, > > > > I recently plonked a dvd into my usb-attached Pioneer DVR-107d only to find > > that the current kernels no longer saw the drive as DVD capable. In fact, > > the kernel no longer saw _any_ features of the drive: sr0: scsi3-mmc drive: > > 0x/0x caddy. After much bisecting and even more blind luck I narrowed the > > problem down to this commit: > > > > commit bdb2b8cab4392ce41ddfbd6773a3da3334daf836 > > Author: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> > > Date: Tue Jun 24 14:03:14 2008 -0400 > > > > [SCSI] erase invalid data returned by device > > > > This patch (as1108) fixes a problem that can occur with certain USB > > mass-storage devices: They return invalid data together with a residue > > indicating that the data should be ignored. Rather than leave the > > invalid data in a transfer buffer, where it can get misinterpreted, > > the patch clears the invalid portion of the buffer. > > > > This solves a problem (wrong write-protect setting detected) reported > > by Maciej Rutecki and Peter Teoh. If this affected your device then the device must not report residues correctly. If you provide the device's entry in /proc/bus/usb/devices, I'll write a patch adding a blacklist entry for it. It would help if you could also provide a usbmon trace showing what happens when you plug the drive in. Instructions are in the kernel source file Documentation/usb/usbmon.txt. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
