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Commit b5595a07 authored by Mathias Nyman's avatar Mathias Nyman Committed by Greg Kroah-Hartman
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xhci: process isoc TD properly when there was a transaction error mid TD.



commit 5372c65e upstream.

The last TRB of a isoc TD might not trigger an event if there was
an error event for a TRB mid TD. This is seen on a NEC Corporation
uPD720200 USB 3.0 Host

After an error mid a multi-TRB TD the xHC should according to xhci 4.9.1
generate events for passed TRBs with IOC flag set if it proceeds to the
next TD. This event is either a copy of the original error, or a
"success" transfer event.

If that event is missing then the driver and xHC host get out of sync as
the driver is still expecting a transfer event for that first TD, while
xHC host is already sending events for the next TD in the list.
This leads to
"Transfer event TRB DMA ptr not part of current TD" messages.

As a solution we tag the isoc TDs that get error events mid TD.
If an event doesn't match the first TD, then check if the tag is
set, and event points to the next TD.
In that case give back the fist TD and process the next TD normally

Make sure TD status and transferred length stay valid in both cases
with and without final TD completion event.

Reported-by: default avatarMichał Pecio <michal.pecio@gmail.com>
Closes: https://lore.kernel.org/linux-usb/20240112235205.1259f60c@foxbook/


Tested-by: default avatarMichał Pecio <michal.pecio@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarMathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20240125152737.2983959-4-mathias.nyman@linux.intel.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent a78f36f3
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