7d2901f809
The present change is a bug fix for AVB link iteratively up/down.
Steps to reproduce:
- start AVB TX stream (Using aplay via MSE),
- disconnect+reconnect the eth cable,
- after a reconnection the eth connection goes iteratively up/down
without user interaction,
- this may heal after some seconds or even stay for minutes.
As the documentation specifies, the "renesas,no-ether-link" option
should be used when a board does not provide a proper AVB_LINK signal.
There is no need for this option enabled on RCAR H3/M3 Salvator-X/XS
and ULCB starter kits since the AVB_LINK is correctly handled by HW.
Choosing to keep or remove the "renesas,no-ether-link" option will
have impact on the code flow in the following ways:
- keeping this option enabled may lead to unexpected behavior since
the RX & TX are enabled/disabled directly from adjust_link function
without any HW interrogation,
- removing this option, the RX & TX will only be enabled/disabled after
HW interrogation. The HW check is made through the LMON pin in PSR
register which specifies AVB_LINK signal value (0 - at low level;
1 - at high level).
In conclusion, the present change is also a safety improvement because
it removes the "renesas,no-ether-link" option leading to a proper way
of detecting the link state based on HW interrogation and not on
software heuristic.
Fixes: dc36965a8905 ("arm64: dts: r8a7796: salvator-x: Enable EthernetAVB")
Fixes: 6fa501c549aa ("arm64: dts: r8a7795: enable EthernetAVB on Salvator-X")
Signed-off-by: Bogdan Mirea <Bogdan-Stefan_Mirea@mentor.com>
Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. 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.