On 01/15/2018 11:41 AM, Simon Horman wrote:
> Regarding Salvator-X and ULCB boards, Bogdan Mirea says:
>
> 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.
>
> On examination of the documentation for the V3M Starter Kit (v3msk) this
> change seems necessary as AVB0_LINK is documented as being connected.
>
> Fixes: a6b1b7359074 ("arm64: dts: renesas: v3msk: add EtherAVB support")
> Cc: Bogdan Mirea <Bogdan-Stefan_Mirea@xxxxxxxxxx>
> Cc: Vladimir Zapolskiy <vladimir_zapolskiy@xxxxxxxxxx>
> Cc: Sergei Shtylyov <sergei.shtylyov@xxxxxxxxxxxxxxxxxx>
> Signed-off-by: Simon Horman <horms+renesas@xxxxxxxxxxxx>
NAK on this one -- I can't mount NFS root any more.
MBR, Sergei
