Messages in this thread | | | Date | Thu, 11 Apr 2024 10:18:07 +0300 | From | Mathias Nyman <> | Subject | Re: xhci_hcd 0000:00:14.0: ERROR Transfer event TRB DMA ptr not part of current TD ep_index 1 comp_code 1 |
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On 10.4.2024 10.59, Paul Menzel wrote: > Dear Mathias, dear Michał, > > > Am 09.04.24 um 13:22 schrieb Mathias Nyman: >> On 8.4.2024 22.05, Michał Pecio wrote: >>>> It's also possible this TD/TRB was cancelled due to the disconnect. >>>> Could be that even if driver removes the TD from the list and cleans >>>> out the TRB from the ring buffer (turns TRB to no-op) hardware may >>>> have read ahead and cached the TRB, and process it anyway. >>> >>> I thought about it, but my debug patch says that the missing TD was >>> freed by finish_td(), which is called on TDs considered completed by >>> hardware. A cancelled TD would show giveback_invalidated_tds(). >>> >>> Anyway, we now have new information from the reporter. My v2 patch >>> keeps a log of the last five events processed on each transfer ring >>> and dumps the log on TRB mismatch errors. >>> >>> Unfortunately, it looks like the host controller is broken and signals >>> completion of those transfers twice. The log below shows two distinct >>> events for TRB 32959a1c0 and that the coresponding TD has just been >>> freed by finish_td(). >> >> The trace confirms this, we get double completion events for several >> Isoc TRBs. These double completions are seen after a transaction >> error on the same device (different endpoint). > >> Transfer events for TRB ..a1c0 twice, with a transaction error in between: >> <idle>-0 [000] d.h2. 33819.709897: xhci_handle_event: EVENT: TRB 000000032959a1c0 status 'Success' len 0 slot 6 ep 2 type 'Transfer Event' flags e:c >> <idle>-0 [000] d.h2. 33819.709904: xhci_handle_event: EVENT: TRB 000000041547d010 status 'USB Transaction Error' len 4 slot 6 ep 15 type 'Transfer Event' flags e:c >> systemd-journal-395 [000] d.H1. 33819.711886: xhci_handle_event: EVENT: TRB 000000032959a1c0 status 'Success' len 0 slot 6 ep 2 type 'Transfer Event' flags e:c >> >> Transfer events for TRB ..a1d0 twice (the next TRB) >> systemd-journal-395 [000] d.H1. 33819.712001: xhci_handle_event: EVENT: TRB 000000032959a1d0 status 'Success' len 0 slot 6 ep 2 type 'Transfer Event' flags e:c >> systemd-journal-395 [000] d.H1. 33819.712059: xhci_handle_event: EVENT: TRB 000000032959a1d0 status 'Success' len 0 slot 6 ep 2 type 'Transfer Event' flags e:c >> >> Transfer events for TRB ..a1e0 twice >> systemd-journal-395 [000] d.H1. 33819.712139: xhci_handle_event: EVENT: TRB 000000032959a1e0 status 'Success' len 0 slot 6 ep 2 type 'Transfer Event' flags e:c >> systemd-journal-395 [000] d.h1. 33819.712871: xhci_handle_event: EVENT: TRB 000000032959a1e0 status 'Success' len 0 slot 6 ep 2 type 'Transfer Event' flags e:c >> >> etc.. >> >> Driver can cope with these extra events, but if this is common we should >> probably handle it silently and not concern users with that ERROR message. > > Thank you for the detailed analysis. Excuse my ignorance, but do you have an idea, what this Sennheiser USB headset does differently than other USB devices? Additionally, is this a known problem with this Intel xHCI controller, meaning, is there an errata about this problem?
There are a few related erratas in older 9 series chipsets that possibly could explain this, but those issues are no longer listed for newer chipsets.
The Sennheiser headset is a full-speed (FS) device that use 192 byte Isoch transfers.
Series 9 chipset xHC has issues with exactly those FS Isoch transfers over 189 bytes, see " 1. USB Isoch In Transfer Error Issue"
There are some issues related to FS device removal: " 13. USB Full-/low-speed Device Removal Issue"
And some related to resending transfer events for "chached" TRBs after FS device disconnect/reconnect. "25. USB xHCI may Execute a Stale Transfer Request Block (TRB)"
https://www.intel.co.jp/content/dam/www/public/us/en/documents/specification-updates/9-series-chipset-pch-spec-update.pdf
Thanks Mathias
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