On Sat, 1 Jul 2006, Andrew Morton wrote: > Begin forwarded message: > > Date: Fri, 30 Jun 2006 15:17:13 +0200 > From: DervishD <[EMAIL PROTECTED]> > To: Linux-kernel <[email protected]> > Subject: usb-storage device wrongly seen as "write protect is on" > > > Hi all :) > > I'm having a problem with an usb-storage device (namely a Inovix > IMP65 MP3 player): when I plug it and I try to mount it, the sd_mod > driver sees it write protected, so I cannot mount it read-write. > > If I remount it as read-write (as root, of course), I have > success and I can use the device normally, being able to write to it > without problems. If, instead, I manually unload sd_mod and load it > again, then this time the device is NOT seen as write protected (the > sd_mod driver says that "write protect is off"). > > All this happens using kernel 2.4.32. If using Ubuntu kernel > 2.6.15, the same problem happens, but Ubuntu probes the device twice > and the second time the "write protect is off" message appears. It > mounts the device "ro", anyway. I've tested with two different USB > ports, an ALi 2.0 (driver EHCI+OHCI) and a builtin VIA686 (driver > UHCI) with the same results. > > If I plug the device with the write protect switch on (that is, > the device IS *really* write protected), the sd_mod driver sees it as > "write protect is off" and I can mount it "rw"... but I cannot write > anything! > > The same device works OK in WinXP without any driver (well, with > the default USB disk driver), so I'm not sure if the problem is on > the device (in fact, it works OK after remounting "rw" by hand or > manually reloading sd_mod) or in the kernel drivers (which I find > very unlikely, since similar Inovix players work as-is). > > If you need more information, feel free to ask, and if this is a > known issue I will very happy if you could point me to the > appropriate place. I've googled a bit with no success...
This does not sound like a problem with the USB stack. You can find out for certain what's really happening by using the usbmon facility in 2.6.17. Instructions are in the kernel source file Documentation/usb/usbmon.txt. My best guess at this point is that the device sometimes sends incorrect information about the write-protect setting back to the computer. Alan Stern Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ [email protected] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
