On Mon, Mar 06, 2023 at 01:36:51PM +0100, Benjamin Tissoires wrote: > On Mon, Mar 6, 2023 at 11:49 AM Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> wrote: > > On Thu, Mar 02, 2023 at 06:06:06PM +0100, Benjamin Tissoires wrote: > > > On Mar 01 2023, Andy Shevchenko wrote: > > > > On Tue, Feb 28, 2023 at 01:05:54PM -0600, Daniel Kaehn wrote: ... [1]: https://stackoverflow.com/a/60855157/2511795 > > > Thanks Andy for your help here, and thanks for that link. > > > > > > I am trying to test Danny's patch as I want to use it for my HID CI, > > > being an owner of a CP2112 device myself. > > > > > > The current setup is using out of the tree patches [2] which are > > > implementing a platform i2c-hid support and some manual addition of a > > > I2C-HID device on top of it. This works fine but gets busted every now > > > and then when the tree sees a change that conflicts with these patches. > > > > > > So with Danny's series, I thought I could have an SSDT override to > > > declare that very same device instead of patching my kernel before > > > testing it. > > > > > > Of course, it gets tricky because I need to run that under qemu. > > > > > > I am currently stuck at the "sharing the firmware_node from usb with > > > HID" step and I'd like to know if you could help me. > > > > > > On my laptop, if I plug the CP2112 (without using a USB hub), I can get: > > > > > > $> ls -l /sys/bus/hid/devices/0003:10C4:EA90.* > > > lrwxrwxrwx. 1 root root 0 Mar 2 17:02 /sys/bus/hid/devices/0003:10C4:EA90.0079 -> ../../../devices/pci0000:00/0000:00:14.0/usb2/2-9/2-9:1.0/0003:10C4:EA90.0079 > > > $> ls -l /sys/bus/usb/devices/2-9*/firmware_node > > > lrwxrwxrwx. 1 root root 0 Mar 2 17:03 /sys/bus/usb/devices/2-9:1.0/firmware_node -> ../../../../../LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/device:15/device:16/device:25 > > > lrwxrwxrwx. 1 root root 0 Mar 2 17:02 /sys/bus/usb/devices/2-9/firmware_node -> ../../../../LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/device:15/device:16/device:25 > > > > > > So AFAIU the USB device is properly assigned a firmware node. My dsdt > > > also shows the "Device (RHUB)" and I guess everything is fine. > > > > Yes, so far so good. > > > > > However, playing with qemu is not so easy. > > > > > > I am running qemu with the following arguments (well, almost because I > > > have a wrapper script on top of it and I also run the compiled kernel > > > from the current tree): > > > > > > #> qemu-system-x86_64 -bios /usr/share/edk2/ovmf/OVMF_CODE.fd \ > > > -netdev user,id=hostnet0 \ > > > -device virtio-net-pci,netdev=hostnet0 \ > > > -m 4G \ > > > -enable-kvm \ > > > -cpu host \ > > > -device qemu-xhci -usb \ > > > -device 'usb-host,vendorid=0x10c4,productid=0xea90' \ > > > -cdrom ~/Downloads/Fedora-Workstation-Live-x86_64-37-1.7.iso > > > > Side question, where can I get those blobs from (EDKII and Fedora Live CD)? > > I'm using Debian unstable. > > You can install the ovmf package in debian[3], which should have a > similar file. > For the Fedora livecd -> https://getfedora.org/fr/workstation/download/ > but any other distribution with a recent enough kernel should show the > same. Thank you! > > > And this is what I get: > > > > > > #> ls -l /sys/bus/hid/devices/0003:10C4:EA90.* > > > lrwxrwxrwx 1 root root 0 Mar 2 16:10 /sys/bus/hid/devices/0003:10C4:EA90.0001 -> ../../../devices/pci0000:00/0000:00:06.0/usb2/2-1/2-1:1.0/0003:10C4:EA90.0001 > > > > > > #> ls -l /sys/bus/usb/devices/2-1*/firmware_node > > > ls: cannot access '/sys/bus/usb/devices/2-1*/firmware_node': No such file or directory > > > > > > Looking at the DSDT, I do not see any reference to the USB hub, so I > > > wonder if the firmware_node needs to be populated first in the DSDT. > > > > So, where QEMU takes DSDT (ACPI tables in general) from? Can you patch that? > > I believe that's the problem in qemu. > > That's a good question and it's one I am not sure I have the answer to. > I would have assumed that the DSDT was in the OVMF firmware, but given > that we can arbitrarily add command line arguments, I believe it > probably just provides a baseline and then we are screwed. The OVMF bios > is compiled only once, so I doubt there is any mechanism to > enable/disable a component in the DSDT, or make it dynamically > generated. We have two ways of filling missing parts: 1) update the original source of DSDT (firmware or bootloader, whichever provides that); 2) adding an overlay. The 2) works _if and only if_ there is *no* existing object in the tables. In such cases, you can simply provide a *full* hierarchy. See an example of PCI devices in the kernel documentation on how to do that. I believe something similar can be done for USB. > > > Also note that if I plug the CP2112 over a docking station, I lose the > > > firmware_node sysfs entries on the host too. > > > > This seems like a lack of firmware node propagating in the USB hub code in > > the Linux kernel. > > That would make a lot of sense. > > FWIW, in the VM I see a firmware node on the pci controller itself: > #> ls -l /sys/devices/pci0000\:00/0000\:00\:06.0/firmware_node > lrwxrwxrwx 1 root root 0 Mar 6 12:24 /sys/devices/pci0000:00/0000:00:06.0/firmware_node -> ../../LNXSYSTM:00/LNXSYBUS:00/PNP0A03:00/device:07 > > And one the host, through a USB hub: > > #> ls -l /sys/bus/hid/devices/0003:10C4:EA90.* > lrwxrwxrwx. 1 root root 0 Mar 6 13:26 /sys/bus/hid/devices/0003:10C4:EA90.007C -> ../../../devices/pci0000:00/0000:00:14.0/usb2/2-8/2-8.2/2-8.2.4/2-8.2.4:1.0/0003:10C4:EA90.007C > #> ls -l /sys/bus/usb/devices/2-8*/firmware_node > lrwxrwxrwx. 1 root root 0 Mar 2 16:53 /sys/bus/usb/devices/2-8:1.0/firmware_node -> ../../../../../LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/device:15/device:16/device:1e > lrwxrwxrwx. 1 root root 0 Mar 2 16:53 /sys/bus/usb/devices/2-8/firmware_node -> ../../../../LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/device:15/device:16/device:1e > > Note that the firmware node propagation stopped at 2-8, and 2.8.2 is not > having a firmware node. It would be nice if you can run `grep -H 15 /sys/bus/acpi/devices/*/status`, filter out unneeded ones, and for the rest also print their paths: `cat filtered_list_of_acpi_devs | while read p; do grep -H . $p/path; done` With this we will see what devices are actually present and up and running in the system and what their paths in the ACPI namespace. > > > Do you think it would be achievable to emulate that over qemu and use a > > > mainline kernel without patches? > > > > As long as qemu provides correct DSDT it should work I assume. > > Just to be sure I understand, for this to work, we need the DSDT to > export a "Device(RHUB)"? Not sure I understand the term "export" here. We need a description of the (to describe) missing parts. > Or if we fix the USB fw_node propagation, could we just overwrite > "\_SB_.PCI0.S30_"? "\_SB_.PCI0.S30_" is the name the ACPI is giving to > the USB port in my VM case AFAIU. I have no idea what is the S30 node. [2] https://gitlab.freedesktop.org/bentiss/gitlab-kernel-ci/-/tree/master/VM [3] https://packages.debian.org/buster/all/ovmf/filelist -- With Best Regards, Andy Shevchenko
