Hi, Eyal Lebedinsky <eyal@xxxxxxxxxxxxxx> writes: > On 15/08/2021 16.28, Greg KH wrote: >> On Sun, Aug 15, 2021 at 09:32:06AM +1000, Eyal Lebedinsky wrote: >>> I have an external 4-way USB3.0 hub (I actually have two of them) That do not behave as expected. >>> It is an XCD XCDESSUSBH4BK. It is unpowered. I am on fedora 34, kernel 5.13.8-200.fc34.x86_64 >>> >>> For starters, I found that attaching a USB SSD does not allow booting from it. >> That is up to your BIOS, not Linux. > > Attaching the USB SSD directly to the PC does boot from it though. right, booting happens way before the OS gets a chance to run. Sounds like a BIOS issue. >>> I then found that when attaching my phone it is not recognized. >> In what way? >> >>> I searched the hub model and IDs but did not find relevant information. >>> Is there an official list of supported hubs (or devices)? >> No, as any list would instantly be out of date. >> >>> Here is what it looks like. >>> >>> When the hub is attached (no phone) I see >>> Bus 001 Device 048: ID 0bda:5411 Realtek Semiconductor Corp. RTS5411 Hub >>> and >>> /: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/16p, 480M >>> |__ Port 5: Dev 5, If 0, Class=Hub, Driver=hub/4p, 480M >>> |__ Port 2: Dev 48, If 0, Class=Hub, Driver=hub/4p, 480M >>> Attaching the phone does not add a device. >>> >>> Detaching/attaching the hub (with the phone already plugged in) I get >>> Bus 001 Device 052: ID 04e8:6860 Samsung Electronics Co., Ltd Galaxy A5 (MTP) >>> Bus 001 Device 051: ID 0bda:5411 Realtek Semiconductor Corp. RTS5411 Hub >>> and >>> /: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/16p, 480M >>> |__ Port 5: Dev 5, If 0, Class=Hub, Driver=hub/4p, 480M >>> |__ Port 2: Dev 51, If 0, Class=Hub, Driver=hub/4p, 480M >>> |__ Port 1: Dev 52, If 1, Class=Communications, Driver=cdc_acm, 480M >>> |__ Port 1: Dev 52, If 2, Class=CDC Data, Driver=cdc_acm, 480M >>> |__ Port 1: Dev 52, If 0, Class=Imaging, Driver=, 480M >>> |__ Port 1: Dev 52, If 3, Class=Vendor Specific Class, Driver=, 480M >>> and the phone is recognized and accessible as MTP device. >> Great, so when does this not work? This shows a successful device >> found. > > Yes, this does show success, but earlier there is this failure shown: > ## plug phone: > (no new messages) > > In other words, the system did not notice the phone when it was > plugged into that hub. does anything work when plugged to that hub? Is the hub self-powered or bus powered? > I then attached the hub to the machine with the phone already plugged > into it and it was noticed. > > My suspicion is that the hub is at fault and it fails to report the > (phone plugged in) event so linux probably has no knowledge of this. > > What I failed to mention is that plugging a USB disk into this hub IS > recognized as expected. Something is not happy between the phone and > this hub. > > Plugging the phone to other USB 3.0 ports on this machine is > recognized properly. do you have other hubs around to test? -- balbi
