> On Mar 31, 2020, at 11:07 AM, John Donnelly <john.p.donnelly@xxxxxxxxxx> wrote: > > > >> On Mar 31, 2020, at 9:17 AM, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: >> >> On Mon, 30 Mar 2020, John Donnelly wrote: >> >>> The debug method produces the following: >>> >>> iommu=on ( no BCM is discovered ) >>> >>> [ 9.911027] hub 4-0:1.0: state 7 ports 6 chg 0000 evt 0000 >>> [ 9.923028] usb 3-3: new high-speed USB device number 2 using xhci_hcd >>> [ 9.950106] In hub_port_connect .. init >>> [ 9.963879] usb 3-3: udev 2, busnum 3, minor = 257 >>> [ 9.963882] usb 3-3: New USB device found, idVendor=0424, >>> idProduct=2660, bcdDevice= 8.01 >>> [ 9.978980] usb 3-3: New USB device strings: Mfr=0, Product=0, >>> SerialNumber=0 >>> [ 9.994524] usb 3-3: usb_probe_device >>> [ 9.994527] usb 3-3: configuration #1 chosen from 1 choice >>> [ 9.994790] usb 3-3: adding 3-3:1.0 (config #1, interface 0) >>> [ 9.994826] hub 3-3:1.0: usb_probe_interface >>> [ 9.994828] hub 3-3:1.0: usb_probe_interface - got id >>> [ 9.994831] hub 3-3:1.0: USB hub found >>> [ 10.008224] hub 3-3:1.0: 2 ports detected >>> [ 10.021669] hub 3-3:1.0: compound device; port removable status: FR >>> [ 10.021671] hub 3-3:1.0: individual port power switching >>> [ 10.021672] hub 3-3:1.0: individual port over-current protection >>> [ 10.021674] hub 3-3:1.0: Single TT >>> [ 10.021676] hub 3-3:1.0: TT requires at most 8 FS bit times (666 ns) >>> [ 10.021678] hub 3-3:1.0: power on to power good time: 100ms >>> [ 10.021753] hub 3-3:1.0: local power source is good >>> [ 10.021872] hub 3-3:1.0: enabling power on all ports >>> [ 10.022120] hub 2-1:1.0: state 7 ports 8 chg 0000 evt 0000 >>> [ 10.127115] hub 3-3:1.0: state 7 ports 2 chg 0000 evt 0000 >>> [ 10.327902] i8042: Can't read CTR while initializing i8042 >>> >>> >>> Produces this configuration without the BCM devices : >>> >>> >>> lsusb -t >>> /: Bus 04.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/6p, 5000M >>> /: Bus 03.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/15p, 480M >>> |__ Port 3: Dev 2, If 0, Class=Hub, Driver=hub/2p, 480M >>> /: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=ehci-pci/2p, 480M >>> |__ Port 1: Dev 2, If 0, Class=Hub, Driver=hub/8p, 480M >>> /: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=ehci-pci/2p, 480M >>> |__ Port 1: Dev 2, If 0, Class=Hub, Driver=hub/6p, 480M >>> >>> >>> >>> BCM is discovered intel_iommu=off : >>> >>> >>> [ 8.947539] usb 4-3: adding 4-3:1.0 (config #1, interface 0) >>> [ 8.947569] hub 4-3:1.0: usb_probe_interface >>> [ 8.947571] hub 4-3:1.0: usb_probe_interface - got id >>> [ 8.947574] hub 4-3:1.0: USB hub found >>> [ 8.960496] usb 3-1: skipped 1 descriptor after interface >>> [ 8.960499] usb 3-1: skipped 1 descriptor after interface >>> [ 8.960562] hub 4-3:1.0: 2 ports detected >>> [ 8.974067] usb 3-1: default language 0x0409 >>> [ 8.974074] hub 4-3:1.0: compound device; port removable status: FR >>> [ 8.974075] hub 4-3:1.0: individual port power switching >>> [ 8.974077] hub 4-3:1.0: individual port over-current protection >>> [ 8.974079] hub 4-3:1.0: Single TT >>> [ 8.974081] hub 4-3:1.0: TT requires at most 8 FS bit times (666 ns) >>> [ 8.974083] hub 4-3:1.0: power on to power good time: 100ms >>> [ 8.974157] hub 4-3:1.0: local power source is good >>> [ 8.974259] hub 4-3:1.0: enabling power on all ports >>> [ 8.979469] usb 3-1: udev 2, busnum 3, minor = 257 >>> [ 8.979473] usb 3-1: New USB device found, idVendor=03f0, >>> idProduct=7029, bcdDevice= 0.02 >>> [ 8.994797] usb 3-1: New USB device strings: Mfr=1, Product=2, >>> SerialNumber=0 >>> [ 9.010633] usb 3-1: Product: Virtual Keyboard >>> [ 9.024416] usb 3-1: Manufacturer: BMC >>> [ 9.037858] usb 3-1: usb_probe_device >>> [ 9.037860] usb 3-1: configuration #1 chosen from 1 choice >>> [ 9.039418] usb 3-1: adding 3-1:1.0 (config #1, interface 0) >>> [ 9.041507] usb 3-1: adding 3-1:1.1 (config #1, interface 1) >>> [ 9.076272] hub 4-3:1.0: state 7 ports 2 chg 0000 evt 0000 >>> >>> I am not accustomed to looking the USB Bus.port.dev mappings , obviously >>> with BCM discovered there are 05 Bus instead of 4 . >>> >>> /: Bus 05.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/6p, 5000M >>> /: Bus 04.Port 1: Dev 1, Class=root_hub, Driver=xhci_hcd/15p, 480M >>> |__ Port 3: Dev 2, If 0, Class=Hub, Driver=hub/2p, 480M >>> /: Bus 03.Port 1: Dev 1, Class=root_hub, Driver=uhci_hcd/2p, 12M >>> |__ Port 1: Dev 2, If 0, Class=Human Interface Device, >>> Driver=usbhid, 12M >>> |__ Port 1: Dev 2, If 1, Class=Human Interface Device, >>> Driver=usbhid, 12M >>> /: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=ehci-pci/2p, 480M >>> |__ Port 1: Dev 2, If 0, Class=Hub, Driver=hub/8p, 480M >>> /: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=ehci-pci/2p, 480M >>> |__ Port 1: Dev 2, If 0, Class=Hub, Driver=hub/6p, 480M >> >> It seems pretty clear that your system (or at least the BMC part) >> doesn't work as intended when the iommu is turned on. >> >>> Here are the pci mappings: >>> >>> [ 6.381615] input: BMC Virtual Keyboard as >>> /devices/pci0000:00/0000:00:1c.2/0000:01:00.4/usb3/3-1/3-1:1.0/0003:03F0:7029.0001/input/input1 >>> [ 6.463638] hid-generic 0003:03F0:7029.0001: input,hidraw0: USB HID >>> v1.01 Keyboard [BMC Virtual Keyboard ] on usb-0000:01:00.4-1/input0 >>> [ 6.496589] input: BMC Virtual Keyboard as >>> /devices/pci0000:00/0000:00:1c.2/0000:01:00.4/usb3/3-1/3-1:1.1/0003:03F0:7029.0002/input/input2 >>> [ 6.529449] hid-generic 0003:03F0:7029.0002: input,hidraw1: USB HID >>> v1.01 Mouse [BMC Virtual Keyboard ] on usb-0000:01:00.4-1/input1 >>> [ 6.563139] usbcore: registered new interface driver usbhid >>> [ 6.580222] usbhid: USB HID core driver >> >> I don't know why you call these "pci mappings". They have nothing to >> do with PCI, and the last two lines don't talk about mappings at all. >> >>> The last activity done seen on both traces is : >>> >>> " enabling power on all ports " >> >> Why do you say this is the last activity seen on both traces? In both >> of the log extracts you included above there are plenty of lines >> following those "enabling power" messages. >> >>> Is this when the BCM discovery is suppose to occur ? In the function >>> example is when the udev appears: >>> >>> usb 3-1: udev 2, busnum 3, minor = 257 >> >> The BCM discovery is supposed to occur at the time you see it in the >> second log extract above. >> >> One thing I didn't notice before: With iommu=off, you get an entire new >> USB host controller and bus. It is called bus 3, and neither it nor >> the 3-1 device (mouse and keyboard) is present when iommu=on. In >> fact, by comparing the listings you can see that buses 4 and 5 (with >> iommu=off) are really the same as buses 3 and 4 (with iommu=on). >> >> I'd say that your BMC does not work with iommu=on, and it is that >> failure which causes these extra devices not to be discovered. In >> fact, they appear not be real physical devices at all, but rather >> virtual devices created by the BMC firmware. >> >> If you want to find out why the BMC doesn't work with iommu=on, you >> should ask the company that manufactured your computer's motherboard. >> They are probably the only people who know the answer. >> >> Alan Stern >> > > > Hi Alan. > > Thank you for your assistance and insight. I’ve tried older kernels (4.14, and 4.18 ) with iommu=on > and the BMC is recognized . This is obviously a regression somewhere along the way. > > > Let me do some more bisecting. > > Thank you, > JD > Hi , One more follow up question. How does a X86 kernel know where to look for USB buses/control registers ? I am aware PowerPC has a device-tree that is passed by reference from UBoot that contains known devices. For the BCM device : Bus 03.Port 1: Dev 1, Class=root_hub, Driver=uhci_hcd/2p, 12M Is there a corresponding register set I can examine ?
