From mboxrd@z Thu Jan  1 00:00:00 1970
From: Arnaud Patard (Rtp) <arnaud.patard@rtp-net.org>
Subject: Re: [RFC PATCH] net: stmmac: enable EEE in MII, GMII or RGMII only
Date: Thu, 14 Dec 2017 13:41:11 +0100
Message-ID: <87ind9fpnc.fsf@lechat.rtp-net.org>
References: <20171205102809.4347-1-jbrunet@baylibre.com>
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Content-Type: text/plain
Cc: Giuseppe Cavallaro <peppe.cavallaro@st.com>,
        Alexandre Torgue <alexandre.torgue@st.com>,
        netdev@vger.kernel.org, linux-amlogic@lists.infradead.org,
        linux-kernel@vger.kernel.org
To: Jerome Brunet <jbrunet@baylibre.com>
Return-path: <linux-kernel-owner@vger.kernel.org>
In-Reply-To: <20171205102809.4347-1-jbrunet@baylibre.com> (Jerome Brunet's
        message of "Tue, 5 Dec 2017 11:28:09 +0100")
Sender: linux-kernel-owner@vger.kernel.org
List-Id: netdev.vger.kernel.org

Jerome Brunet <jbrunet@baylibre.com> writes:

> Note in the databook - Section 4.4 - EEE :
> " The EEE feature is not supported when the MAC is configured to use the
> TBI, RTBI, SMII, RMII or SGMII single PHY interface. Even if the MAC
> supports multiple PHY interfaces, you should activate the EEE mode only
> when the MAC is operating with GMII, MII, or RGMII interface."
>
> Applying this restriction solves a stability issue observed on Amlogic
> gxl platforms operating with RMII interface and the internal PHY.

I was having the issue on my libretech AML-S905X-CC / potato board. With
this patch, I've not been able to trigger it at all. Without it and with
my test case, I was able to trigger the hang several times reliably.

Any hope to see this merged ?

>
> Fixes: 83bf79b6bb64 ("stmmac: disable at run-time the EEE if not supported")
> Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>

Tested-by: Arnaud Patard <arnaud.patard@rtp-net.org>