> Do you see the problem with single devices? If I connect only one device to system then I did not see this issue. Usually I will use 8 devices(all with the same firmware) for testing. I tried different method to get some clue. First I disconnected all the devices and rebooted the system and later connected only one device and observed hci0 related debug print statements in the kernel log. Waited for 16mins idle, but did not get –EPIPE. Oct 8 16:41:46 banunxcas29 kernel: [ 488.018751] usb 1-1.5.1.7: new full speed USB device number 13 using ehci_hcd Oct 8 16:41:46 banunxcas29 kernel: [ 488.093487] usb 1-1.5.1.7: New USB device found, idVendor=0451, idProduct=2036 Oct 8 16:41:46 banunxcas29 kernel: [ 488.093494] usb 1-1.5.1.7: New USB device strings: Mfr=0, Product=1, SerialNumber=0 Oct 8 16:41:46 banunxcas29 kernel: [ 488.093499] usb 1-1.5.1.7: Product: General Purpose USB Hub Oct 8 16:41:46 banunxcas29 kernel: [ 488.094581] hub 1-1.5.1.7:1.0: USB hub found Oct 8 16:41:46 banunxcas29 kernel: [ 488.094811] hub 1-1.5.1.7:1.0: 2 ports detected Oct 8 16:41:46 banunxcas29 kernel: [ 488.261141] usb 1-1.5.2: new full speed USB device number 14 using ehci_hcd Oct 8 16:41:46 banunxcas29 kernel: [ 488.323983] usb 1-1.5.2: device descriptor read/64, error -32 Oct 8 16:41:47 banunxcas29 kernel: [ 488.518202] usb 1-1.5.2: New USB device found, idVendor=0a12, idProduct=0001 Oct 8 16:41:47 banunxcas29 kernel: [ 488.518208] usb 1-1.5.2: New USB device strings: Mfr=0, Product=0, SerialNumber=0 Oct 8 16:41:47 banunxcas29 kernel: [ 488.551389] Bluetooth: Core ver 2.16 Oct 8 16:41:47 banunxcas29 kernel: [ 488.551402] NET: Registered protocol family 31 Oct 8 16:41:47 banunxcas29 kernel: [ 488.551404] Bluetooth: HCI device and connection manager initialized Oct 8 16:41:47 banunxcas29 kernel: [ 488.551406] Bluetooth: HCI socket layer initialized Oct 8 16:41:47 banunxcas29 kernel: [ 488.551408] Bluetooth: L2CAP socket layer initialized Oct 8 16:41:47 banunxcas29 kernel: [ 488.551411] Bluetooth: SCO socket layer initialized Oct 8 16:41:47 banunxcas29 kernel: [ 488.565663] Bluetooth: Generic Bluetooth USB driver ver 0.6 Oct 8 16:41:47 banunxcas29 kernel: [ 488.565693] intf ffff880128640800 id ffffffffa0197f00 Oct 8 16:41:47 banunxcas29 kernel: [ 488.580231] hci0 Oct 8 16:41:47 banunxcas29 kernel: [ 488.580236] hci0 Oct 8 16:41:47 banunxcas29 kernel: [ 488.580258] intf ffff880128641000 id ffffffffa0197f00 Oct 8 16:41:47 banunxcas29 kernel: [ 488.580296] usbcore: registered new interface driver btusb Oct 8 16:41:47 banunxcas29 kernel: [ 488.580480] hci0 Oct 8 16:41:47 banunxcas29 kernel: [ 488.580486] hci0 Oct 8 16:41:47 banunxcas29 kernel: [ 488.580503] hci0 Oct 8 16:41:47 banunxcas29 kernel: [ 488.581314] hci0 urb ffff880131dbe3c0 status 0 count 6 Later connected one more device to system and noticed hci1 related debug print statements in the kernel log. Waited for 20mins idle and now also not received –EPIPE. Oct 8 16:57:44 banunxcas29 kernel: [ 1443.815276] usb 1-1.5.3: new full speed USB device number 17 using ehci_hcd Oct 8 16:57:45 banunxcas29 kernel: [ 1444.400987] usb 1-1.5.3: New USB device found, idVendor=0a12, idProduct=0001 Oct 8 16:57:45 banunxcas29 kernel: [ 1444.400993] usb 1-1.5.3: New USB device strings: Mfr=0, Product=0, SerialNumber=0 Oct 8 16:57:45 banunxcas29 kernel: [ 1444.403218] intf ffff880124c45800 id ffffffffa0197f00 Oct 8 16:57:45 banunxcas29 kernel: [ 1444.403360] hci1 Oct 8 16:57:45 banunxcas29 kernel: [ 1444.403364] hci1 Oct 8 16:57:45 banunxcas29 kernel: [ 1444.403500] intf ffff880124c44c00 id ffffffffa0197f00 Oct 8 16:57:45 banunxcas29 kernel: [ 1444.403511] hci1 Oct 8 16:57:45 banunxcas29 kernel: [ 1444.403515] hci1 Oct 8 16:57:45 banunxcas29 kernel: [ 1444.403529] hci1 Oct 8 16:57:45 banunxcas29 kernel: [ 1444.404872] hci1 urb ffff880129162840 status 0 count 6 Later connected third device(hci2) and after 2mins observed –EPIPE for hci2(hci2 urb ffff880124f11cc0 status -32 count 0) Oct 8 17:18:21 banunxcas29 kernel: [ 2677.069853] usb 1-1.5.4: new full speed USB device number 18 using ehci_hcd Oct 8 17:18:21 banunxcas29 kernel: [ 2677.681729] usb 1-1.5.4: New USB device found, idVendor=0a12, idProduct=0001 Oct 8 17:18:21 banunxcas29 kernel: [ 2677.681735] usb 1-1.5.4: New USB device strings: Mfr=0, Product=0, SerialNumber=0 Oct 8 17:18:21 banunxcas29 kernel: [ 2677.683689] intf ffff880119c3b400 id ffffffffa0197f00 Oct 8 17:18:21 banunxcas29 kernel: [ 2677.683886] hci2 Oct 8 17:18:21 banunxcas29 kernel: [ 2677.683889] hci2 Oct 8 17:18:21 banunxcas29 kernel: [ 2677.684083] intf ffff880119c3a800 id ffffffffa0197f00 Oct 8 17:18:21 banunxcas29 kernel: [ 2677.684161] hci2 Oct 8 17:18:21 banunxcas29 kernel: [ 2677.684166] hci2 Oct 8 17:18:21 banunxcas29 kernel: [ 2677.684184] hci2 Oct 8 17:18:21 banunxcas29 kernel: [ 2677.685364] hci2 urb ffff880124f11cc0 status 0 count 6 Oct 8 17:18:22 banunxcas29 kernel: [ 2678.126333] hci2 urb ffff880124f11cc0 status 0 count 6 Oct 8 17:20:20 banunxcas29 kernel: [ 2795.645039] hci2 urb ffff880124f11cc0 status -32 count 0 Oct 8 17:20:20 banunxcas29 kernel: [ 2795.646013] hci2 Later connected 4th device(hci3) and now repeatedly getting –EPIPE for hci3 and hci2 Oct 8 17:44:14 banunxcas29 kernel: [ 4226.073252] usb 1-1.5.5: new full speed USB device number 19 using ehci_hcd Oct 8 17:44:14 banunxcas29 kernel: [ 4226.746971] usb 1-1.5.5: New USB device found, idVendor=0a12, idProduct=0001 Oct 8 17:44:14 banunxcas29 kernel: [ 4226.746977] usb 1-1.5.5: New USB device strings: Mfr=0, Product=0, SerialNumber=0 Oct 8 17:44:14 banunxcas29 kernel: [ 4226.749042] intf ffff880124c47400 id ffffffffa0197f00 Oct 8 17:44:14 banunxcas29 kernel: [ 4226.749403] hci3 Oct 8 17:44:14 banunxcas29 kernel: [ 4226.749407] hci3 Oct 8 17:44:14 banunxcas29 kernel: [ 4226.749526] intf ffff880124c47000 id ffffffffa0197f00 Oct 8 17:44:14 banunxcas29 kernel: [ 4226.749679] hci3 Oct 8 17:44:14 banunxcas29 kernel: [ 4226.749684] hci3 Oct 8 17:44:14 banunxcas29 kernel: [ 4226.749700] hci3 Oct 8 17:44:14 banunxcas29 kernel: [ 4226.750520] hci3 urb ffff8801344e6a80 status 0 count 6 Oct 8 17:49:45 banunxcas29 kernel: [ 4556.495180] hci3 urb ffff8801344e6a80 status -32 count 0 Oct 8 17:49:45 banunxcas29 kernel: [ 4556.496341] hci3 Oct 8 17:51:24 banunxcas29 kernel: [ 4655.170274] hci2 urb ffff880131c6ea80 status -32 count 0 Oct 8 17:51:24 banunxcas29 kernel: [ 4655.170345] hci3 urb ffff880124dfb480 status -32 count 0 Oct 8 17:51:24 banunxcas29 kernel: [ 4655.171381] hci2 Oct 8 17:51:24 banunxcas29 kernel: [ 4655.171759] hci3 Oct 8 18:00:24 banunxcas29 kernel: [ 5193.920586] hci3 urb ffff880124f11d80 status -32 count 0 Oct 8 18:00:24 banunxcas29 kernel: [ 5193.921890] hci3 Oct 8 18:00:24 banunxcas29 kernel: [ 5193.928470] hci3 urb ffff880124f11d80 status -32 count 0 Oct 8 18:00:24 banunxcas29 kernel: [ 5193.929511] hci3 Oct 8 18:00:24 banunxcas29 kernel: [ 5193.933570] hci3 urb ffff880124f11d80 status -32 count 0 Oct 8 18:00:24 banunxcas29 kernel: [ 5193.934402] hci3 Oct 8 18:00:24 banunxcas29 kernel: [ 5193.940425] hci3 urb ffff880124f11d80 status -32 count 0 Oct 8 18:00:24 banunxcas29 kernel: [ 5193.941531] hci3 Oct 8 18:05:18 banunxcas29 kernel: [ 5487.003279] hci3 urb ffff880124f11d80 status -32 count 0 Oct 8 18:05:18 banunxcas29 kernel: [ 5487.004528] hci3 Oct 8 18:06:24 banunxcas29 kernel: [ 5552.844852] hci3 urb ffff880124f11d80 status -32 count 0 Oct 8 18:06:24 banunxcas29 kernel: [ 5552.846068] hci3 Oct 8 18:06:24 banunxcas29 kernel: [ 5552.860809] hci3 urb ffff880124f11d80 status -32 count 0 Oct 8 18:06:24 banunxcas29 kernel: [ 5552.861776] hci3 Oct 8 18:06:24 banunxcas29 kernel: [ 5552.867701] hci3 urb ffff880124f11d80 status -32 count 0 Oct 8 18:06:24 banunxcas29 kernel: [ 5552.868651] hci3 Oct 8 18:06:24 banunxcas29 kernel: [ 5552.874669] hci2 urb ffff880124f11cc0 status -32 count 0 Oct 8 18:06:24 banunxcas29 kernel: [ 5552.874738] hci3 urb ffff880124f183c0 status -32 count 0 Oct 8 18:06:24 banunxcas29 kernel: [ 5552.875772] hci2 Oct 8 18:06:24 banunxcas29 kernel: [ 5552.875949] hci3 Oct 8 18:06:24 banunxcas29 kernel: [ 5552.877734] hci2 urb ffff880124f11cc0 status -32 count 0 Oct 8 18:06:24 banunxcas29 kernel: [ 5552.877800] hci3 urb ffff880124f11e40 status -32 count 0 Oct 8 18:06:24 banunxcas29 kernel: [ 5552.878720] hci3 Oct 8 18:06:24 banunxcas29 kernel: [ 5552.878922] hci2 Oct 8 18:06:24 banunxcas29 kernel: [ 5553.098220] hci3 urb ffff880124f11cc0 status -32 count 0 Oct 8 18:06:24 banunxcas29 kernel: [ 5553.098291] hci2 urb ffff880124f11e40 status -32 count 0 Oct 8 18:06:24 banunxcas29 kernel: [ 5553.099158] hci2 Oct 8 18:06:24 banunxcas29 kernel: [ 5553.099339] hci3 Oct 8 18:06:24 banunxcas29 kernel: [ 5553.101145] hci3 urb ffff880124f11e40 status -32 count 0 Oct 8 18:06:24 banunxcas29 kernel: [ 5553.102165] hci3 Oct 8 18:06:24 banunxcas29 kernel: [ 5553.107198] hci3 urb ffff880124f11e40 status -32 count 0 Oct 8 18:06:24 banunxcas29 kernel: [ 5553.108141] hci3 Oct 8 18:06:24 banunxcas29 kernel: [ 5553.121160] hci3 urb ffff880124f11e40 status -32 count 0 Oct 8 18:06:24 banunxcas29 kernel: [ 5553.122130] hci3 Oct 8 18:06:24 banunxcas29 kernel: [ 5553.133127] hci2 urb ffff880124f11cc0 status -32 count 0 Oct 8 18:06:24 banunxcas29 kernel: [ 5553.133196] hci3 urb ffff880124f11e40 status -32 count 0 Oct 8 18:06:24 banunxcas29 kernel: [ 5553.134075] hci3 Oct 8 18:06:24 banunxcas29 kernel: [ 5553.134300] hci2 Oct 8 18:06:24 banunxcas29 kernel: [ 5553.136143] hci3 urb ffff880124f11cc0 status -32 count 0 Oct 8 18:06:24 banunxcas29 kernel: [ 5553.136176] hci2 urb ffff880124f11e40 status -32 count 0 I ran hcidump for each hci device separately, but it does not show any activity during EPIPE occurrence. It clearly tells that device not producing stalls , looks like issue might be in between btusb and ehci_hcd\hub. What might the best way to recover and avoid spurious stalls? Thanks, Naveen On Wed, Oct 8, 2014 at 4:14 PM, Oliver Neukum <oneukum@xxxxxxx> wrote: > On Wed, 2014-10-08 at 15:51 +0530, Naveen Kumar Parna wrote: >> hcidump does not show anything when the stalls happen. > > There is nothing in all logs. Do you see the problem > with single devices? > > Regards > Oliver > > -- To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html