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. Thanks & best regards, Tim -- 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
