Hi, I am using v3.5 kernel and running a test where I disconnect a SS MSC device while a big file is being written to it. I am also watching the lsusb output in parallel. Expectation is that SS MSC device should immediately disappear from lsusb output but sometime I see that SS MSC is listed for 30 seconds and then only disappears. Log is copied below. Looking further into the issue shows that in failing case an URB is not given back by XHCI driver and so SCSI layer unlinks it after 30second of timeout. This URB was actually given to XHCI host controller and a disconnect happens while packet transfer was in progress. I looked at XHCI driver and could not find request being aborted by driver (in xhci_free_dev() fn) before issuing disable slot or reset device command. What is expectation in this scenario? Is it XHCI driver responsibility to abort and giveback all the request (as in EHCI using endpoint_disable()) OR host controller hardware should abort and post an error completion event for each request? Why XHCI driver doesn't have an endpoint_disable() implemented as done for other controller? =============== Working case ==================== [ 3406.676989] Port Status Change Event for port 2 [ 3406.711530] get port status, actual port 1 status = 0x4202c0 [ 3406.711531] Get port status returned 0x4102c0 [ 3406.711629] clear port connect change, actual port 1 status = 0x4002c0 [ 3406.711664] clear port link state change, actual port 1 status = 0x2c0 [ 3406.721606] [E.f2e0b980.Transfer error on endpoint <=== URB submitted here but gets transfer error [ 3406.721742] Cleaning up stalled endpoint ring [ 3406.721744] Finding segment containing stopped TRB. [ 3406.721746] Finding endpoint context [ 3406.721747] Finding segment containing last TRB in TD. [ 3406.721749] Cycle state = 0x1 [ 3406.721750] New dequeue segment = f2073880 (virtual) [ 3406.721752] New dequeue pointer = 0x337be380 (DMA) [ 3406.721754] Queueing new dequeue state [ 3406.721756] Set TR Deq Ptr cmd, new deq seg = f2073880 (0x337be000 dma), new deq ptr = f37be380 (0x337be380 dma), new cycle = 1 [ 3406.721758]// Ding dong! [ 3406.721855] Giveback URB f2e0b980, len = 0, expected = 31, status = -71 <=== URB given back by XHCI driver ================================================= =============== Non Working case ================ [ 2971.576389] Port Status Change Event for port 2 [ 2971.576487] [E.f2d0c480. <=== URB submitted but no error. [ 2971.585007] get port status, actual port 1 status = 0x4202c0 [ 2971.585079] Get port status returned 0x4102c0 [ 2971.585178] clear port connect change, actual port 1 status = 0x4002c0 [ 2971.585213] clear port link state change, actual port 1 status = 0x2c0 [ 2971.640030] get port status, actual port 1 status = 0x2d1 [ 2971.640031] Get port status returned 0x2d1 [ 2971.696029] get port status, actual port 1 status = 0x2d1 [ 2971.696031] Get port status returned 0x2d1 [ 2971.900031] get port status, actual port 1 status = 0x2d1 [ 2971.900034] Get port status returned 0x2d1 [ 2972.060480] Port Status Change Event for port 2 [ 2972.104039] get port status, actual port 1 status = 0x2802a0 [ 2972.104041] Get port status returned 0x3002a0 [ 2972.104079] clear port reset change, actual port 1 status = 0x802a0 [ 2972.104108] clear port warm(BH) reset change, actual port 1 status = 0x2a0 [ 2972.104138] clear port link state change, actual port 1 status = 0x2a0 [ 2972.104144] usb 6-2: USB disconnect, device number 6 <=== 30 seconds gap ==== > [ 3002.080058] Cancel URB f2d0c480, dev 2, ep 0x81, starting at offset 0x337ad060 <== SCSI layer cancelling URB after 30 seconds [ 3002.080063]// Ding dong! [ 2972.060569] Stopped on Transfer TRB [ 3002.080817] Removing canceled TD starting at 0x337ad060 (dma). [ 3002.080820] Finding segment containing stopped TRB. [ 3002.080822] Finding endpoint context [ 3002.080823] Finding segment containing last TRB in TD. [ 3002.080825] Cycle state = 0x0 [ 3002.080827] New dequeue segment = f71628f0 (virtual) [ 3002.080828] New dequeue pointer = 0x337ad070 (DMA) [ 3002.080831] Set TR Deq Ptr cmd, new deq seg = f71628f0 (0x337ad000 dma), new deq ptr = f37ad070 (0x337ad070 dma), new cycle = 0 ================================================= Thanks Ajay -- 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
