Takeshi Kihara
ae8ff9c564
[ Upstream commit90d4fa39d0] It is incorrect to specify the no-ether-link property for the AVB device on the Ebisu board. This is because the property should only be used when a board does not provide a proper AVB_LINK signal. However, the Ebisu board does provide this signal. As per87c059e9c3("arm64: dts: renesas: salvator-x: Remove renesas, no-ether-link property") this fixes a bug: 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:8441ef643d("arm64: dts: renesas: r8a77990: ebisu: Enable EthernetAVB") Signed-off-by: Takeshi Kihara <takeshi.kihara.df@renesas.com> [simon: updated changelog] Signed-off-by: Simon Horman <horms+renesas@verge.net.au> Signed-off-by: Sasha Levin <sashal@kernel.org>
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.
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.