On Sunday 13 January 2013 18:42:49 Alex Riesen wrote: > On Sun, Jan 13, 2013 at 5:56 PM, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > > On Sun, 13 Jan 2013, Alex Riesen wrote: > >> > >> Yes, almost. What about khubd hanging when machine is shutdown? > > > > What about it? I have trouble understanding all the descriptions you > > have provided so far, because you talk about several different things > > and change your mind a lot. Can you provide a single, simple scenario > > that illustrates this problem? > > 1. Compile a kernel with deadline elevator as module > 2. Boot into it, make sure the elevator is selected > (I used "elevator=deadline" in the kernel command line) > 3. Insert a FAT formatted mass storage device in an USB2 port > Observe "io scheduler deadline registered" > 4. Pull the stick out, wait a moment, and either shutdown or just > and press alt-sysrq-W: That makes it clear. The elevator probably has scheduled work which cannot finish waiting on a lock and scsi_remove_host() wants to flush work. This is not a USB problem. You need to involve the SCSI people. khubd just stops working because disconnects are processed in its context and the removal deadlocks. Regards Oliver -- 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
