On Sat, 21 Feb 2009 01:45:37 am Alan Stern wrote: > 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. Many thanks. > 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. /proc/bus/usb/devices: T: Bus=01 Lev=01 Prnt=01 Port=06 Cnt=01 Dev#= 3 Spd=480 MxCh= 0 D: Ver= 2.00 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=64 #Cfgs= 1 P: Vendor=05e3 ProdID=0701 Rev= 0.02 S: Manufacturer=Genesyslogic S: Product=USB Mass Storage Device C:* #Ifs= 1 Cfg#= 1 Atr=80 MxPwr= 96mA I:* If#= 0 Alt= 0 #EPs= 2 Cls=08(stor.) Sub=06 Prot=50 Driver=usb-storage E: Ad=81(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms E: Ad=02(O) Atr=02(Bulk) MxPS= 512 Ivl=125us I'll email the usbmod log directly, to save spamming the list with a 100kb attachment. Mike -- 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
