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On 6/25/2024 09:45, Mika Westerberg wrote: > On Tue, Jun 25, 2024 at 05:37:27PM +0300, Mathias Nyman wrote: >> On 24.6.2024 7.59, Mika Westerberg wrote: >>> On Fri, Jun 21, 2024 at 11:30:05AM -0500, Mario Limonciello wrote: >>>> On 6/21/2024 01:19, Mika Westerberg wrote: >>>>> Hi Mario, >>>>> >>>>> On Thu, Jun 20, 2024 at 01:36:56PM -0500, Mario Limonciello wrote: >>>>>> On 6/20/2024 01:41, Mika Westerberg wrote: >>>>>>> +CC Mario from AMD side to check that we are good and don't break >>>>>>> anything accidentally. >>>>>>> >>>>>>> On Wed, Jun 19, 2024 at 04:03:01PM +0300, Mathias Nyman wrote: >>>>>>>> The relationship between a USB4 Host Interface providing USB3 tunnels, >>>>>>>> and tunneled USB3 devices is not represented in device hierarchy. >>>>>>>> >>>>>>>> This caused issues with power managment as devices may suspend and >>>>>>>> resume in incorrect order. >>>>>>>> A device link between the USB4 Host Interface and the USB3 xHCI was >>>>>>>> originally added to solve this, preventing the USB4 Host Interface from >>>>>>>> suspending if the USB3 xHCI Host was still active. >>>>>>>> This unfortunately also prevents USB4 Host Interface from suspending even >>>>>>>> if the USB3 xHCI Host is only serving native non-tunneled USB devices. >>>>>>>> >>>>>>>> Improve the current powermanagement situation by creating device links >>>>>>>> directly from tunneled USB3 devices to the USB4 Host Interface they depend >>>>>>>> on instead of a device link between the hosts. >>>>>>>> This way USB4 host may suspend when the last tunneled device is >>>>>>>> disconnected. >>>>>>>> >>>>>>>> Intel xHCI hosts are capable of reporting if connected USB3 devices are >>>>>>>> tunneled via vendor specific capabilities. >>>>>>>> Use this until a standard way is available. >>>>>>>> >>>>>>>> Mathias Nyman (4): >>>>>>>> xhci: Add USB4 tunnel detection for USB3 devices on Intel hosts >>>>>>>> usb: Add tunneled parameter to usb device structure >>>>>>>> usb: acpi: add device link between tunneled USB3 device and USB4 Host >>>>>>>> Interface >>>>>>>> thunderbolt: Don't create device link from USB4 Host Interface to USB3 >>>>>>>> xHC host >>>>>>>> >>>>>>>> drivers/thunderbolt/acpi.c | 40 ++++++------------------ >>>>>>>> drivers/usb/core/usb-acpi.c | 52 ++++++++++++++++++++++++++++++++ >>>>>>>> drivers/usb/host/xhci-ext-caps.h | 5 +++ >>>>>>>> drivers/usb/host/xhci-hub.c | 29 ++++++++++++++++++ >>>>>>>> drivers/usb/host/xhci.c | 12 ++++++++ >>>>>>>> drivers/usb/host/xhci.h | 1 + >>>>>>>> include/linux/usb.h | 2 ++ >>>>>>>> 7 files changed, 111 insertions(+), 30 deletions(-) >>>>>>>> >>>>>>>> -- >>>>>>>> 2.25.1 >>>>>> >>>>>> Hi Mika, >>>>>> >>>>>> Thanks for looping me in. Unfortunately with this is appears the XHCI >>>>>> controller link never gets created. I've not checked functional impact from >>>>>> this, but I'd guess there "should" be some functional problems too. >>>>> >>>>> Thanks for checking! >>>>> >>>>> I think the code that sets up the device link based on ->tunneled should >>>>> do that always if the hardware cannot tell if this is native or tunneled >>>>> link to keep the existing functionality and only do the "optimization" >>>>> if the hardware is capable of identifying that. >>>>> >>>>> Perhaps it can be a callback provided by the xHCI controller driver >>>>> (->is_tunneled()) that then defaults to true if the >>>>> "usb4-host-interface" property is there and in case of Intel hardware >>>>> also checks the proprietary register? >> >> How about changing the boolean udev->tunneled into a 3 value enum with >> "link_unknown", "link_native", and "link_tunneled" options. >> >> "link_unknown" would be default, xhci driver only changes this to "link_tunneled" or >> "link_native" if the host can detect tunnels. >> >> device link to USB4 host would be created for USB3 devices that have >> "usb4-host-interface" property and udev->tunneled != native. > > Sounds good to me :) I think it's a good idea as well. Could you leave a dynamic debugging statement with the result? I think this could be helpful for rooting out unexpected BIOS problems with this.