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Date: Sat, 13 Apr 2024 11:17:46 +0200
From: =?UTF-8?B?TWljaGHFgg==?= Pecio <michal.pecio@gmail.com>
To: Paul Menzel <pmenzel@molgen.mpg.de>
Cc: Mathias Nyman <mathias.nyman@linux.intel.com>, Mathias Nyman
 <mathias.nyman@intel.com>, LKML <linux-kernel@vger.kernel.org>,
 linux-usb@vger.kernel.org, Niklas Neronin <niklas.neronin@linux.intel.com>
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
Message-ID: <20240413111746.059dd4b7@foxbook>
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> 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?
It uses isochronous out transfers, which off the top of my head are
almost only used for audio playback in the real world.

However, I don't know what it is doing differently from your other USB
headset. A few random hypotheses:
- the other is not a "full speed" device (but it most likely is)
- you haven't tried enough times to reproduce the bug
- you have some software which automatically starts playback to the
  Sennheiser when it's connected, but not to the other headset
- different playback format and different USB packet size, although
  192B/ms corresponds to 16 bit 48kHz stereo - the most comomn format.


As for your bugzilla comment and the list of other TRB mismatch errors
on linux-hardware - yes, these things happen due to a variety of bugs
in host controllers and the driver. They are not all the same bug and
they can't be analyzed or fixed if people don't report them and don't
cooperate in debugging. These messages alone don't provide information
about what specifically went wrong and under which circumstances.


Regards,
Michal