On Wed, 2 May 2018, Nazar Mokrynskyi wrote: > Some more details from my system: > > [ 0.725657] ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver > [ 0.725670] ehci-pci: EHCI PCI platform driver > [ 0.726004] ehci-platform: EHCI generic platform driver > [ 0.726340] ohci_hcd: USB 1.1 'Open' Host Controller (OHCI) Driver > [ 0.726684] ohci-pci: OHCI PCI platform driver > [ 0.727022] ohci-platform: OHCI generic platform driver > [ 0.727356] uhci_hcd: USB Universal Host Controller Interface driver > [ 0.727762] xhci_hcd 0000:00:14.0: xHCI Host Controller > [ 0.728122] xhci_hcd 0000:00:14.0: new USB bus registered, assigned bus number 1 > [ 0.729533] xhci_hcd 0000:00:14.0: hcc params 0x200077c1 hci version 0x100 quirks 0x00009810 > [ 0.729873] xhci_hcd 0000:00:14.0: cache line size of 64 is not supported > [ 0.730972] usb usb1: Manufacturer: Linux 4.15.0-20-generic xhci-hcd > [ 0.733250] xhci_hcd 0000:00:14.0: xHCI Host Controller > [ 0.733580] xhci_hcd 0000:00:14.0: new USB bus registered, assigned bus number 2 > [ 0.734947] usb usb2: Manufacturer: Linux 4.15.0-20-generic xhci-hcd > [ 0.737314] xhci_hcd 0000:03:00.0: xHCI Host Controller > [ 0.737650] xhci_hcd 0000:03:00.0: new USB bus registered, assigned bus number 3 > [ 0.792826] xhci_hcd 0000:03:00.0: hcc params 0x0200ef81 hci version 0x110 quirks 0x00000010 > [ 0.794272] usb usb3: Manufacturer: Linux 4.15.0-20-generic xhci-hcd > [ 0.795715] xhci_hcd 0000:03:00.0: xHCI Host Controller > [ 0.796035] xhci_hcd 0000:03:00.0: new USB bus registered, assigned bus number 4 > [ 0.796331] xhci_hcd 0000:03:00.0: Host supports USB 3.1 Enhanced SuperSpeed > [ 0.797849] usb usb4: Manufacturer: Linux 4.15.0-20-generic xhci-hcd > [ 0.917461] ahci 0000:00:17.0: version 3.0 > [ 0.917754] ahci 0000:00:17.0: AHCI 0001.0301 32 slots 6 ports 6 Gbps 0x3f impl SATA mode > [ 0.918095] ahci 0000:00:17.0: flags: 64bit ncq sntf led clo only pio slum part ems deso sadm sds apst > [ 0.988425] scsi host0: ahci > [ 0.988932] scsi host1: ahci > [ 0.989430] scsi host2: ahci > [ 0.989891] scsi host3: ahci > [ 0.990335] scsi host4: ahci > [ 0.990777] scsi host5: ahci > [ 1.072061] usb 1-9: new high-speed USB device number 2 using xhci_hcd > [ 1.356096] usb 1-10: new high-speed USB device number 3 using xhci_hcd > [ 1.584007] usb 1-9.1: new full-speed USB device number 4 using xhci_hcd > [ 1.812022] usb 1-12: new high-speed USB device number 5 using xhci_hcd > [ 2.040005] usb 1-9.2: new full-speed USB device number 6 using xhci_hcd > [ 7.532036] usb 1-9.3: new full-speed USB device number 7 using xhci_hcd > [ 351.369187] usb 1-9: new high-speed USB device number 8 using xhci_hcd > [ 351.805248] usb 1-9.1: new full-speed USB device number 9 using xhci_hcd > [ 352.053264] usb 1-9.2: new high-speed USB device number 10 using xhci_hcd > [ 357.417231] usb 1-9.3: new full-speed USB device number 11 using xhci_hcd > > usb 1-9 is a 4-port USB hub to which USB mouse, keyboard and sound > card are connected. > > USB hub correctly initializes at high-speed from the start, but sound > card (usb 1-9.2) for some reason only initializes at full-speed, > which causes my issues. > > However, when I unplug USB hub on fully booted system and plug it > back, sound card initializes at high-speed. > > More debugging revealed that sound card connected directly to USB > port on motherboard initializes properly. > > So my current understanding is that there is some kind of an issue > with USB hub handling during system boot. As far as I know, hubs attached at boot time get initialized and handled in exactly the same way as hubs attached afterward. When a device is connected to a high-speed hub, the hardware in the hub is what determines the device's speed. Not the software in the kernel. The kernel just uses whatever speed the hub says to use. Have you tried a different brand of hub, to see if it makes any difference? Alan Stern -- 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
