Alan Stern [EMAIL PROTECTED] wrote: > Jan 10 20:49:08 desktop kernel: scsi113 : SCSI emulation for USB Mass Storage > devices > Jan 10 20:49:08 desktop kernel: usb-storage: device found at 113 > Jan 10 20:49:08 desktop kernel: usb-storage: waiting for device to settle > before scanning > Jan 10 20:49:12 desktop kernel: In bus_reset, srb: 0000010037d71640 > Jan 10 20:49:12 desktop kernel: device: 0000010038e3d000 > Jan 10 20:49:12 desktop kernel: host: 000001002b500c00 > Jan 10 20:49:12 desktop kernel: hostdata: 000001002b549c00 > > This is the first indication of something funny. I can't think how a bus > reset would get initiated by the kernel -- that only happens after a > timeout. Maybe it came from a user program?
Well it can get initiated in the scsi error handler. This can be verified by setting the logging_level (sysctl -w dev.scsi.logging_level=0x4). You probably do not need to do this as I assume what is happening is that with all the plug and unplug that is being initiated that a IO is in flight when the scsi_remove_host functions is called. It looks like we still have to decide on the removal cleanup. Currently scsi_host_cancel being called from scsi_remove_host appears to not do anything as scsi_forget_host removes the devices from the list it iterates over. Also as previously mentioned by you there are races with scsi_mid canceling IOs that might be completing. Both of these issue where mentioned in an old thread (link provided below), but not completely resolved. http://marc.theaimsgroup.com/?t=109630920600005&r=1&w=2 What is needed is for the LLDD to ensure all IO sent through the LLDD's queuecommand functions gets a scsi_done call (even a fail call). The scsi mid applies choke points to stop IO being set to the LLDDs queuecommand, but there can be races during a host removal (you previously mentioned this). This would also imply that scsi mid should not be making the call to scsi_host_cancel (which appears to not do anything anyway). -andmike -- Michael Anderson [EMAIL PROTECTED] ------------------------------------------------------- The SF.Net email is sponsored by: Beat the post-holiday blues Get a FREE limited edition SourceForge.net t-shirt from ThinkGeek. It's fun and FREE -- well, almost....http://www.thinkgeek.com/sfshirt _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
