Hi, during my tests with a Raspberry Pi 2 B with an C-Media audio dongle connected to a powered USB hub, i noticed the enumeration errors below (the device gets finally ernumerated). I tested yesterdays linux-next, 4.17-rc2 and 4.14 but all of them show this behavior, if i plugin the audio dongle into the USB hub.
/: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=dwc2/1p, 480M |__ Port 1: Dev 2, If 0, Class=Hub, Driver=hub/5p, 480M |__ Port 1: Dev 3, If 0, Class=Vendor Specific Class, Driver=smsc95xx, 480M |__ Port 2: Dev 4, If 0, Class=Hub, Driver=hub/4p, 480M |__ Port 3: Dev 8, If 2, Class=Audio, Driver=snd-usb-audio, 12M |__ Port 3: Dev 8, If 0, Class=Audio, Driver=snd-usb-audio, 12M |__ Port 3: Dev 8, If 3, Class=Human Interface Device, Driver=usbhid, 12M |__ Port 3: Dev 8, If 1, Class=Audio, Driver=snd-usb-audio, 12M |__ Port 1: Dev 5, If 0, Class=Hub, Driver=hub/4p, 480M |__ Port 4: Dev 7, If 1, Class=Human Interface Device, Driver=usbhid, 1.5M |__ Port 4: Dev 7, If 0, Class=Human Interface Device, Driver=usbhid, 1.5M The verbose version can be found here: https://gist.github.com/lategoodbye/baa0f8890325f8698664aeb60ecedfd5 Here is an example dmesg after plugin the audio dongle: [ 1176.382877] usb 1-1.2.1.3: new full-speed USB device number 14 using dwc2 [ 1176.516254] dwc2 20980000.usb: dwc2_hc_chhltd_intr_dma: Channel 1 - ChHltd set, but reason is unknown [ 1176.516284] dwc2 20980000.usb: hcint 0x00000402, intsts 0x04200009 [ 1176.516355] dwc2 20980000.usb: dwc2_hc_chhltd_intr_dma: Channel 4 - ChHltd set, but reason is unknown [ 1176.516372] dwc2 20980000.usb: hcint 0x00000402, intsts 0x04200009 [ 1176.516427] dwc2 20980000.usb: dwc2_hc_chhltd_intr_dma: Channel 6 - ChHltd set, but reason is unknown [ 1176.516442] dwc2 20980000.usb: hcint 0x00000402, intsts 0x04200001 [ 1176.518435] dwc2 20980000.usb: dwc2_hc_chhltd_intr_dma: Channel 5 - ChHltd set, but reason is unknown [ 1176.518464] dwc2 20980000.usb: hcint 0x00000402, intsts 0x04200001 [ 1176.518532] dwc2 20980000.usb: dwc2_hc_chhltd_intr_dma: Channel 3 - ChHltd set, but reason is unknown [ 1176.518549] dwc2 20980000.usb: hcint 0x00000402, intsts 0x04200001 [ 1176.518605] dwc2 20980000.usb: dwc2_hc_chhltd_intr_dma: Channel 1 - ChHltd set, but reason is unknown [ 1176.518623] dwc2 20980000.usb: hcint 0x00000402, intsts 0x04200009 [ 1176.520704] dwc2 20980000.usb: dwc2_hc_chhltd_intr_dma: Channel 3 - ChHltd set, but reason is unknown [ 1176.520734] dwc2 20980000.usb: hcint 0x00000402, intsts 0x04200001 [ 1176.520802] dwc2 20980000.usb: dwc2_hc_chhltd_intr_dma: Channel 1 - ChHltd set, but reason is unknown [ 1176.520820] dwc2 20980000.usb: hcint 0x00000402, intsts 0x04200001 [ 1176.520887] dwc2 20980000.usb: dwc2_hc_chhltd_intr_dma: Channel 6 - ChHltd set, but reason is unknown [ 1176.520905] dwc2 20980000.usb: hcint 0x00000402, intsts 0x04200001 [ 1176.521127] usb 1-1.2.1.3: unable to read config index 0 descriptor/all [ 1176.521197] usb 1-1.2.1.3: can't read configurations, error -71 [ 1176.632956] usb 1-1.2.1.3: new full-speed USB device number 15 using dwc2 [ 1176.763789] dwc2 20980000.usb: dwc2_hc_chhltd_intr_dma: Channel 6 - ChHltd set, but reason is unknown [ 1176.763820] dwc2 20980000.usb: hcint 0x00000402, intsts 0x04200001 [ 1176.763890] dwc2 20980000.usb: dwc2_hc_chhltd_intr_dma: Channel 5 - ChHltd set, but reason is unknown [ 1176.763909] dwc2 20980000.usb: hcint 0x00000402, intsts 0x04200001 [ 1176.763998] dwc2 20980000.usb: dwc2_hc_chhltd_intr_dma: Channel 2 - ChHltd set, but reason is unknown [ 1176.764016] dwc2 20980000.usb: hcint 0x00000402, intsts 0x04200009 [ 1177.012371] input: C-Media Electronics Inc. USB PnP Sound Device as /devices/platform/soc/20980000.usb/usb1/1-1/1-1.2/1-1.2.1/1-1.2.1.3/1-1.2.1.3:1.3/0003:0D8C:013C.0008/input/input7 [ 1177.088948] hid-generic 0003:0D8C:013C.0008: input: USB HID v1.00 Device [C-Media Electronics Inc. USB PnP Sound Device] on usb-20980000.usb-1.2.1.3/input3 Best regards -- 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