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3c0d41f141
As shown in the schematic diagram below.There may be a critical
scenario in the current code. If the device does not receive an
pure ack sent by the host due to insufficient receive buffer or
other reasons and triggers a retransmission, the host will always
be in an 'out-of-order' state.The state machine will get stuck.
host device
SEQ3,ACK4 --------->
<--------- SEQ4,ACK4
pure ACK ---------> (not received)
(out-of-order) <--------- SEQ4,ACK4(retransmission)
........
(out-of-order) <--------- SEQ4,ACK4(retransmission)
According to the description in the core specification: "whenever
a reliable packet is received, an acknowledgment shall be generated."
So set H5_TX_ACK_REQ bit to trigger retransmission of pure ack packet
when "out-of-order" occurs.
Signed-off-by: Qiqi Zhang <eddy.zhang@rock-chips.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.