On Tue, 2018-06-26 at 13:52 +0300, Heikki Krogerus wrote: > On Tue, Jun 26, 2018 at 12:10:56PM +0200, Timur Krist?f wrote: > > On Tue, 2018-06-26 at 11:29 +0300, Heikki Krogerus wrote: > > > On Mon, Jun 25, 2018 at 01:09:32PM +0200, Timur Krist?f wrote: > > > > On Mon, 2018-06-25 at 13:11 +0300, Heikki Krogerus wrote: > > > > > +Mika > > > > > > > > > > On Fri, Jun 22, 2018 at 10:12:10AM +0200, Timur Krist?f > > > > > wrote: > > > > > > Hi, > > > > > > > > > > > > I have a Dell XPS 13 9370, which has just Type-C ports. > > > > > > Currently > > > > > > running kernel 4.17.2. I found that plugging in a powered > > > > > > USB > > > > > > hub > > > > > > into > > > > > > the Type-C port does not work. > > > > > > > > > > > > Please let me know if this isn't the correct place to > > > > > > report > > > > > > this > > > > > > problem. Not sure if this is a Dell-specific issue or a > > > > > > Linux- > > > > > > specific > > > > > > issue, so I'm also CCing Mario from Dell. > > > > > > > > > > > > The following test cases were tried: > > > > > > > > > > > > 1. When I plug in the hub to the laptop, and then plug in > > > > > > the > > > > > > peripherals, it works as expected. (This is OK.) > > > > > > > > > > > > 2. But when I plug peripherals into the hub, and then plug > > > > > > it > > > > > > into > > > > > > the > > > > > > laptop, it takes at least 10-30 seconds to detect them. > > > > > > (Until > > > > > > then > > > > > > they don't show up in lsusb.) > > > > > > > > > > > > 3. If the hub is powered and power is connected to the hub > > > > > > before > > > > > > plugging it in, it is not detected at all. Sometimes it is > > > > > > detected > > > > > > after being plugged in for a very long time, but not > > > > > > always. > > > > > > > > > > > > I tried with various different configurations: > > > > > > > > > > > > A. Dell USB Type-C to Type-A adapter with a Speedlink USB > > > > > > 2.0 > > > > > > hub. > > > > > > > > > > > > B. Same Dell C-to-A adapter with the built-in USB 2.0 hub > > > > > > of a > > > > > > Dell > > > > > > P2414H monitor. > > > > > > > > > > > > C. Qoltec USB Type-C to USB 3.0 hub > > > > > > > > > > > > All of these exhibited the same behaviour. When the hub was > > > > > > powered > > > > > > before plugging it in, then they were not recognized at > > > > > > all, > > > > > > when > > > > > > unpowered they were recognized in ~ 30 seconds (which is > > > > > > still > > > > > > too > > > > > > long > > > > > > though). > > > > > > > > > > > > Note that the USB 2.0 hubs both worked correctly with other > > > > > > machines > > > > > > which just had a USB-A port. When plugged into a USB-A > > > > > > port, > > > > > > all > > > > > > the > > > > > > connected peripherals were immediately detected as soon as > > > > > > the > > > > > > hub > > > > > > was > > > > > > plugged in. > > > > > > > > > > > > What might be the issue here? How can I help debug this > > > > > > further? > > > > > > > > > > This could be a problem with the Thunderbolt controller. > > > > > Mika, do > > > > > you > > > > > know if there are any known problems when using self powered > > > > > USB > > > > > hubs? > > > > > > > > > > > > > The issue also happens with the non-Thunderbolt USB Type-C > > > > port, at > > > > least on this laptop. > > > > > > Ah, ic. XPS 9360 has two thunderbolt ports and a standard-A port > > > on > > > the other side. I can see that the standard-A port has been > > > replaced > > > with the USB Type-C port on XPS 9370. > > > > > > > 9360 (2017 model) has two USB 3.0 Type-A ports and one Thunderbolt > > 3 > > Type-C (with 2 PCI-E lanes). > > > > 9370 (2018 model) has one USB 3.1 Type-C, and two Thunderbolt 3 > > Type-C > > ports (with 4 PCI-E lanes). No Type-A ports. This is what I've got. > > > > > Are you able to test if the problem can been seen also in > > > Windows? > > > > I don't have Windows with this machine (it came with Ubuntu). But I > > guess I could try with an evaluation version of Windows, if that is > > helpful. > > It would help confirm if this is a firmware related bug or not.
All right, I will try to test it on Windows as soon as I can. I will keep you guys posted. > > One thing I forgot to ask you. Do you see any messages in your syslog > when the problem happens, and is there any difference in the syslog > messages when compared to the situation where the hub is enumerated > normally? > > Can you send the dmesg output after you have plugged the powered and > non-powered hubs: Right now I have the Dell Type-C to USB 3.0 Type-A adapter with the USB 2.0 hub here. There is a Logitech received plugged into the hub. (So I can quickly see if it works or not.) After some trial-and-error I figured out when it works and when not. Tests were performed on Fedora 28 with kernel 4.17.2. Basically it always works just on the first try. In other words, when I power up the USB 2.0 hub and plug it in, then it works. If I plug it out, but keep it powered and plug it back in again, it stops working. If it was plugged into another computer but kept powered, it does not work with this laptop either. (Until I power the hub off and on again.) It appears that the Thunderbolt and non-Thunderbolt ports behave slightly differently, and the same testcases leave wildly different messages in dmesg. So I will describe what I did and what output I got from dmesg. I. Plain USB 3.1 Type-C (NON-Thunderbolt) port with powered hub: ----------------------- 1. plug the Logitech receiver into the USB 2.0 hub 2. plug the USB 2.0 hub into the Type-C adapter 3. power up the hub 4. plug the Type-C adapter into the laptop Now it works correctly and I see this in dmesg: [ 8442.557096] xhci_hcd 0000:00:14.0: Root hub is not suspended [ 8442.774152] usb 1-1: new high-speed USB device number 33 using xhci_hcd [ 8442.902487] usb 1-1: New USB device found, idVendor=05e3, idProduct=0608, bcdDevice=32.98 [ 8442.902494] usb 1-1: New USB device strings: Mfr=0, Product=1, SerialNumber=0 [ 8442.902499] usb 1-1: Product: USB2.0 Hub [ 8442.904191] hub 1-1:1.0: USB hub found [ 8442.904565] hub 1-1:1.0: 4 ports detected [ 8443.181156] usb 1-1.4: new full-speed USB device number 34 using xhci_hcd [ 8443.261741] usb 1-1.4: New USB device found, idVendor=046d, idProduct=c526, bcdDevice= 5.00 [ 8443.261748] usb 1-1.4: New USB device strings: Mfr=1, Product=2, SerialNumber=0 [ 8443.261752] usb 1-1.4: Product: USB Receiver [ 8443.261756] usb 1-1.4: Manufacturer: Logitech [ 8443.270241] input: Logitech USB Receiver as /devices/pci0000:00/0000:00:14.0/usb1/1-1/1-1.4/1-1.4:1.0/0003:046D:C526.001C/input/input54 [ 8443.271402] hid-generic 0003:046D:C526.001C: input,hidraw0: USB HID v1.11 Mouse [Logitech USB Receiver] on usb-0000:00:14.0-1.4/input0 [ 8443.273201] input: Logitech USB Receiver as /devices/pci0000:00/0000:00:14.0/usb1/1-1/1-1.4/1-1.4:1.1/0003:046D:C526.001D/input/input55 [ 8443.326034] hid-generic 0003:046D:C526.001D: input,hiddev96,hidraw1: USB HID v1.11 Device [Logitech USB Receiver] on usb-0000:00:14.0-1.4/input1 5. plug out the Type-C adapter from the laptop, but keep the hub powered 6. plug it back in (sometimes may need to repeat 5. and 6. a couple of times) Now dmesg doesn't show anything (besides the disconnect messages), and the devices don't show up in lsusb. II: The Thunderbolt port with powered hub: ----------------------------------------- 1. plug the Logitech receiver into the USB 2.0 hub 2. plug the USB 2.0 hub into the Type-C adapter 3. power up the hub 4. plug the Type-C adapter into the laptop This is what I see in dmesg in case of the Thunderbolt port: [ 8681.804696] ACPI BIOS Error (bug): Failure creating [\_GPE.XTBT.SPRT], AE_ALREADY_EXISTS (20180313/dswload2-316) [ 8681.804720] ACPI Error: AE_ALREADY_EXISTS, During name lookup/catalog (20180313/psobject-220) [ 8681.804730] ACPI Error: Method parse/execution failed \_GPE.XTBT, AE_ALREADY_EXISTS (20180313/psparse-516) [ 8681.804744] ACPI Error: Method parse/execution failed \_GPE.XTBT, AE_ALREADY_EXISTS (20180313/psparse-516) [ 8681.804760] ACPI Error: Method parse/execution failed \_GPE._E42, AE_ALREADY_EXISTS (20180313/psparse-516) [ 8681.804775] ACPI Error: AE_ALREADY_EXISTS, while evaluating GPE method [_E42] (20180313/evgpe-509) [ 8681.974615] pci 0000:03:00.0: [8086:15d3] type 01 class 0x060400 [ 8681.974711] pci 0000:03:00.0: enabling Extended Tags [ 8681.974899] pci 0000:03:00.0: supports D1 D2 [ 8681.974904] pci 0000:03:00.0: PME# supported from D0 D1 D2 D3hot D3cold [ 8681.975505] pci 0000:04:00.0: [8086:15d3] type 01 class 0x060400 [ 8681.975600] pci 0000:04:00.0: enabling Extended Tags [ 8681.975737] pci 0000:04:00.0: supports D1 D2 [ 8681.975741] pci 0000:04:00.0: PME# supported from D0 D1 D2 D3hot D3cold [ 8681.975974] pci 0000:04:01.0: [8086:15d3] type 01 class 0x060400 [ 8681.976067] pci 0000:04:01.0: enabling Extended Tags [ 8681.976196] pci 0000:04:01.0: supports D1 D2 [ 8681.976200] pci 0000:04:01.0: PME# supported from D0 D1 D2 D3hot D3cold [ 8681.976422] pci 0000:04:02.0: [8086:15d3] type 01 class 0x060400 [ 8681.976514] pci 0000:04:02.0: enabling Extended Tags [ 8681.976640] pci 0000:04:02.0: supports D1 D2 [ 8681.976644] pci 0000:04:02.0: PME# supported from D0 D1 D2 D3hot D3cold [ 8681.976870] pci 0000:04:04.0: [8086:15d3] type 01 class 0x060400 [ 8681.976962] pci 0000:04:04.0: enabling Extended Tags [ 8681.977099] pci 0000:04:04.0: supports D1 D2 [ 8681.977104] pci 0000:04:04.0: PME# supported from D0 D1 D2 D3hot D3cold [ 8681.977407] pci 0000:03:00.0: PCI bridge to [bus 04-6d] [ 8681.977428] pci 0000:03:00.0: bridge window [mem 0xac000000-0xda0fffff] [ 8681.977442] pci 0000:03:00.0: bridge window [mem 0x60000000-0xa9ffffff 64bit pref] [ 8681.977590] pci 0000:04:00.0: PCI bridge to [bus 05] [ 8681.977609] pci 0000:04:00.0: bridge window [mem 0xda000000-0xda0fffff] [ 8681.977755] pci 0000:04:01.0: PCI bridge to [bus 06-38] [ 8681.977774] pci 0000:04:01.0: bridge window [mem 0xac000000-0xc3efffff] [ 8681.977788] pci 0000:04:01.0: bridge window [mem 0x60000000-0x7fffffff 64bit pref] [ 8681.978000] pci 0000:39:00.0: [8086:15d4] type 00 class 0x0c0330 [ 8681.978061] pci 0000:39:00.0: reg 0x10: [mem 0xc3f00000-0xc3f0ffff] [ 8681.978186] pci 0000:39:00.0: enabling Extended Tags [ 8681.978358] pci 0000:39:00.0: supports D1 D2 [ 8681.978364] pci 0000:39:00.0: PME# supported from D0 D1 D2 D3hot D3cold [ 8681.978727] pci 0000:04:02.0: PCI bridge to [bus 39] [ 8681.978746] pci 0000:04:02.0: bridge window [mem 0xc3f00000-0xc3ffffff] [ 8681.978912] pci 0000:04:04.0: PCI bridge to [bus 3a-6d] [ 8681.978931] pci 0000:04:04.0: bridge window [mem 0xc4000000-0xd9ffffff] [ 8681.978945] pci 0000:04:04.0: bridge window [mem 0x80000000-0xa9ffffff 64bit pref] [ 8681.979004] pci_bus 0000:04: Allocating resources [ 8681.979073] pci 0000:04:01.0: bridge window [io 0x1000-0x0fff] to [bus 06-38] add_size 1000 [ 8681.979094] pci 0000:04:02.0: bridge window [io 0x1000-0x0fff] to [bus 39] add_size 1000 [ 8681.979104] pci 0000:04:02.0: bridge window [mem 0x00100000-0x000fffff 64bit pref] to [bus 39] add_size 200000 add_align 100000 [ 8681.979124] pci 0000:04:04.0: bridge window [io 0x1000-0x0fff] to [bus 3a-6d] add_size 1000 [ 8681.979146] pci 0000:03:00.0: bridge window [io 0x1000-0x0fff] to [bus 04-6d] add_size 3000 [ 8681.979158] pci 0000:03:00.0: BAR 13: no space for [io size 0x3000] [ 8681.979164] pci 0000:03:00.0: BAR 13: failed to assign [io size 0x3000] [ 8681.979172] pci 0000:03:00.0: BAR 13: no space for [io size 0x3000] [ 8681.979177] pci 0000:03:00.0: BAR 13: failed to assign [io size 0x3000] [ 8681.979196] pci 0000:04:02.0: BAR 15: no space for [mem size 0x00200000 64bit pref] [ 8681.979201] pci 0000:04:02.0: BAR 15: failed to assign [mem size 0x00200000 64bit pref] [ 8681.979207] pci 0000:04:01.0: BAR 13: no space for [io size 0x1000] [ 8681.979212] pci 0000:04:01.0: BAR 13: failed to assign [io size 0x1000] [ 8681.979218] pci 0000:04:02.0: BAR 13: no space for [io size 0x1000] [ 8681.979223] pci 0000:04:02.0: BAR 13: failed to assign [io size 0x1000] [ 8681.979230] pci 0000:04:04.0: BAR 13: no space for [io size 0x1000] [ 8681.979235] pci 0000:04:04.0: BAR 13: failed to assign [io size 0x1000] [ 8681.979245] pci 0000:04:04.0: BAR 13: no space for [io size 0x1000] [ 8681.979250] pci 0000:04:04.0: BAR 13: failed to assign [io size 0x1000] [ 8681.979259] pci 0000:04:02.0: BAR 15: no space for [mem size 0x00200000 64bit pref] [ 8681.979264] pci 0000:04:02.0: BAR 15: failed to assign [mem size 0x00200000 64bit pref] [ 8681.979270] pci 0000:04:02.0: BAR 13: no space for [io size 0x1000] [ 8681.979275] pci 0000:04:02.0: BAR 13: failed to assign [io size 0x1000] [ 8681.979281] pci 0000:04:01.0: BAR 13: no space for [io size 0x1000] [ 8681.979287] pci 0000:04:01.0: BAR 13: failed to assign [io size 0x1000] [ 8681.979294] pci 0000:04:00.0: PCI bridge to [bus 05] [ 8681.979308] pci 0000:04:00.0: bridge window [mem 0xda000000-0xda0fffff] [ 8681.979326] pci 0000:04:01.0: PCI bridge to [bus 06-38] [ 8681.979338] pci 0000:04:01.0: bridge window [mem 0xac000000-0xc3efffff] [ 8681.979348] pci 0000:04:01.0: bridge window [mem 0x60000000-0x7fffffff 64bit pref] [ 8681.979362] pci 0000:04:02.0: PCI bridge to [bus 39] [ 8681.979374] pci 0000:04:02.0: bridge window [mem 0xc3f00000-0xc3ffffff] [ 8681.979393] pci 0000:04:04.0: PCI bridge to [bus 3a-6d] [ 8681.979404] pci 0000:04:04.0: bridge window [mem 0xc4000000-0xd9ffffff] [ 8681.979413] pci 0000:04:04.0: bridge window [mem 0x80000000-0xa9ffffff 64bit pref] [ 8681.979427] pci 0000:03:00.0: PCI bridge to [bus 04-6d] [ 8681.979438] pci 0000:03:00.0: bridge window [mem 0xac000000-0xda0fffff] [ 8681.979448] pci 0000:03:00.0: bridge window [mem 0x60000000-0xa9ffffff 64bit pref] [ 8681.982576] xhci_hcd 0000:39:00.0: xHCI Host Controller [ 8681.983208] xhci_hcd 0000:39:00.0: new USB bus registered, assigned bus number 3 [ 8681.984441] xhci_hcd 0000:39:00.0: hcc params 0x200077c1 hci version 0x110 quirks 0x00009810 [ 8681.984929] usb usb3: New USB device found, idVendor=1d6b, idProduct=0002, bcdDevice= 4.17 [ 8681.984934] usb usb3: New USB device strings: Mfr=3, Product=2, SerialNumber=1 [ 8681.984939] usb usb3: Product: xHCI Host Controller [ 8681.984942] usb usb3: Manufacturer: Linux 4.17.2-200.fc28.x86_64 xhci-hcd [ 8681.984946] usb usb3: SerialNumber: 0000:39:00.0 [ 8681.985554] hub 3-0:1.0: USB hub found [ 8681.985580] hub 3-0:1.0: 2 ports detected [ 8681.987075] xhci_hcd 0000:39:00.0: xHCI Host Controller [ 8681.987529] xhci_hcd 0000:39:00.0: new USB bus registered, assigned bus number 4 [ 8681.987542] xhci_hcd 0000:39:00.0: Host supports USB 3.1 Enhanced SuperSpeed [ 8681.987653] usb usb4: New USB device found, idVendor=1d6b, idProduct=0003, bcdDevice= 4.17 [ 8681.987660] usb usb4: New USB device strings: Mfr=3, Product=2, SerialNumber=1 [ 8681.987665] usb usb4: Product: xHCI Host Controller [ 8681.987670] usb usb4: Manufacturer: Linux 4.17.2-200.fc28.x86_64 xhci-hcd [ 8681.987675] usb usb4: SerialNumber: 0000:39:00.0 [ 8681.988727] hub 4-0:1.0: USB hub found [ 8681.988755] hub 4-0:1.0: 2 ports detected [ 8682.309046] usb 3-1: new high-speed USB device number 2 using xhci_hcd [ 8682.436630] usb 3-1: New USB device found, idVendor=05e3, idProduct=0608, bcdDevice=32.98 [ 8682.436637] usb 3-1: New USB device strings: Mfr=0, Product=1, SerialNumber=0 [ 8682.436641] usb 3-1: Product: USB2.0 Hub [ 8682.438386] hub 3-1:1.0: USB hub found [ 8682.438734] hub 3-1:1.0: 4 ports detected [ 8682.716037] usb 3-1.4: new full-speed USB device number 3 using xhci_hcd [ 8682.796883] usb 3-1.4: New USB device found, idVendor=046d, idProduct=c526, bcdDevice= 5.00 [ 8682.796890] usb 3-1.4: New USB device strings: Mfr=1, Product=2, SerialNumber=0 [ 8682.796894] usb 3-1.4: Product: USB Receiver [ 8682.796898] usb 3-1.4: Manufacturer: Logitech [ 8682.808864] input: Logitech USB Receiver as /devices/pci0000:00/0000:00:1c.4/0000:03:00.0/0000:04:02.0/0000:39:00.0/usb3/3-1/3-1.4/3-1.4:1.0/0003:046D:C526.0020/input/input58 [ 8682.810077] hid-generic 0003:046D:C526.0020: input,hidraw0: USB HID v1.11 Mouse [Logitech USB Receiver] on usb-0000:39:00.0-1.4/input0 [ 8682.812674] input: Logitech USB Receiver as /devices/pci0000:00/0000:00:1c.4/0000:03:00.0/0000:04:02.0/0000:39:00.0/usb3/3-1/3-1.4/3-1.4:1.1/0003:046D:C526.0021/input/input59 [ 8682.865189] hid-generic 0003:046D:C526.0021: input,hiddev96,hidraw1: USB HID v1.11 Device [Logitech USB Receiver] on usb-0000:39:00.0-1.4/input1 5. plug out the Type-C adapter from the laptop, but keep the hub powered Now dmesg tells me this: [ 8762.294229] usb 3-1: USB disconnect, device number 2 [ 8762.294235] usb 3-1.4: USB disconnect, device number 3 [ 8762.468918] xhci_hcd 0000:39:00.0: xHCI host controller not responding, assume dead [ 8762.468947] xhci_hcd 0000:39:00.0: HC died; cleaning up [ 8762.487958] xhci_hcd 0000:39:00.0: remove, state 4 [ 8762.487974] usb usb4: USB disconnect, device number 1 [ 8762.488794] xhci_hcd 0000:39:00.0: USB bus 4 deregistered [ 8762.488977] xhci_hcd 0000:39:00.0: remove, state 1 [ 8762.488992] usb usb3: USB disconnect, device number 1 [ 8762.502228] xhci_hcd 0000:39:00.0: Host halt failed, -19 [ 8762.502237] xhci_hcd 0000:39:00.0: Host not accessible, reset failed. [ 8762.502546] xhci_hcd 0000:39:00.0: USB bus 3 deregistered [ 8762.522010] pci_bus 0000:04: Allocating resources [ 8762.522077] pcieport 0000:04:01.0: bridge window [io 0x1000-0x0fff] to [bus 06-38] add_size 1000 [ 8762.522099] pcieport 0000:04:02.0: bridge window [io 0x1000-0x0fff] to [bus 39] add_size 1000 [ 8762.522109] pcieport 0000:04:02.0: bridge window [mem 0x00100000-0x000fffff 64bit pref] to [bus 39] add_size 200000 add_align 100000 [ 8762.522130] pcieport 0000:04:04.0: bridge window [io 0x1000-0x0fff] to [bus 3a-6d] add_size 1000 [ 8762.522153] pcieport 0000:03:00.0: bridge window [io 0x1000-0x0fff] to [bus 04-6d] add_size 3000 [ 8762.522169] pcieport 0000:03:00.0: BAR 13: no space for [io size 0x3000] [ 8762.522175] pcieport 0000:03:00.0: BAR 13: failed to assign [io size 0x3000] [ 8762.522183] pcieport 0000:03:00.0: BAR 13: no space for [io size 0x3000] [ 8762.522189] pcieport 0000:03:00.0: BAR 13: failed to assign [io size 0x3000] [ 8762.522209] pcieport 0000:04:02.0: BAR 15: no space for [mem size 0x00200000 64bit pref] [ 8762.522215] pcieport 0000:04:02.0: BAR 15: failed to assign [mem size 0x00200000 64bit pref] [ 8762.522221] pcieport 0000:04:01.0: BAR 13: no space for [io size 0x1000] [ 8762.522227] pcieport 0000:04:01.0: BAR 13: failed to assign [io size 0x1000] [ 8762.522233] pcieport 0000:04:02.0: BAR 13: no space for [io size 0x1000] [ 8762.522238] pcieport 0000:04:02.0: BAR 13: failed to assign [io size 0x1000] [ 8762.522244] pcieport 0000:04:04.0: BAR 13: no space for [io size 0x1000] [ 8762.522250] pcieport 0000:04:04.0: BAR 13: failed to assign [io size 0x1000] [ 8762.522258] pcieport 0000:04:04.0: BAR 13: no space for [io size 0x1000] [ 8762.522262] pcieport 0000:04:04.0: BAR 13: failed to assign [io size 0x1000] [ 8762.522273] pcieport 0000:04:02.0: BAR 15: no space for [mem size 0x00200000 64bit pref] [ 8762.522278] pcieport 0000:04:02.0: BAR 15: failed to assign [mem size 0x00200000 64bit pref] [ 8762.522284] pcieport 0000:04:02.0: BAR 13: no space for [io size 0x1000] [ 8762.522289] pcieport 0000:04:02.0: BAR 13: failed to assign [io size 0x1000] [ 8762.522295] pcieport 0000:04:01.0: BAR 13: no space for [io size 0x1000] [ 8762.522300] pcieport 0000:04:01.0: BAR 13: failed to assign [io size 0x1000] [ 8767.504962] pcieport 0000:04:00.0: Refused to change power state, currently in D3 [ 8767.507086] pci_bus 0000:05: busn_res: [bus 05] is released [ 8767.507374] pci_bus 0000:06: busn_res: [bus 06-38] is released [ 8767.507801] pci_bus 0000:39: busn_res: [bus 39] is released [ 8767.508159] pci_bus 0000:3a: busn_res: [bus 3a-6d] is released [ 8767.508339] pci_bus 0000:04: busn_res: [bus 04-6d] is released 6. plug it back in to the laptop Now I don't get any more messages from dmesg and it doesn't work anymore. The devices don't show up is lsusb. 7. plug out the Type-C adapter from the laptop, also un-power the hub 8. power the hub again 9. plug it back in to the laptop. Now we're back to the start, it works again and it displays the same dmesg messages as when it was working for the first time. Other notes: ------------ When the hub is not powered, it always works and dmesg outputs the same messages as the first (working) testcases. In both the I. and II. cases, if the hub was previously plugged into another computer, and then into this laptop, it never works, until I power the hub off and on again. The ACPI message seen with the Thunderbolt port appears the same as the one that appears on bootup, and is confirmed to be a BIOS bug by Mario (from Dell) here: https://bugzilla.kernel.org/show_bug.cgi?id=199557 ------------------------ Sorry for the very long email. Hope this helps, Tim -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
