From mboxrd@z Thu Jan 1 00:00:00 1970 From: Martin Blumenstingl Subject: Re: [RFC PATCH net v2 0/3] Fix OdroidC2 Gigabit Tx link issue Date: Thu, 24 Nov 2016 15:40:51 +0100 Message-ID: References: <1479742524-30222-1-git-send-email-jbrunet@baylibre.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Return-path: In-Reply-To: <1479742524-30222-1-git-send-email-jbrunet@baylibre.com> Sender: linux-kernel-owner@vger.kernel.org To: Jerome Brunet Cc: netdev@vger.kernel.org, devicetree@vger.kernel.org, Florian Fainelli , Carlo Caione , Kevin Hilman , Giuseppe Cavallaro , Alexandre TORGUE , Andre Roth , Neil Armstrong , linux-amlogic@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org List-Id: devicetree@vger.kernel.org Hi Jerome, On Mon, Nov 21, 2016 at 4:35 PM, Jerome Brunet wrote: > This patchset fixes an issue with the OdroidC2 board (DWMAC + RTL8211F). > Initially reported as a low Tx throughput issue at gigabit speed, the > platform enters LPI too often. This eventually break the link (both Tx > and Rx), and require to bring the interface down and up again to get the > Rx path working again. > > The root cause of this issue is not fully understood yet but disabling EEE > advertisement on the PHY prevent this feature to be negotiated. > With this change, the link is stable and reliable, with the expected > throughput performance. I have just sent a series which allows configuring the TX delay on the MAC (dwmac-meson8b glue) side: [0] Disabling the TX delay generated by the MAC fixes TX throughput for me, even when leaving EEE enabled in the RTL8211F PHY driver! Unfortunately the RTL8211F PHY is a black-box for the community because there is no public datasheeet available. *maybe* (pure speculation!) they're enabling the TX delay based on some internal magic only when EEE is enabled. Jerome, could you please re-test the behavior on your Odroid-C2 when you have EEE still enabled but the TX-delay disabled? In my case throughput is fine, and "$ ethtool -S eth0 | grep lpi" gives: irq_tx_path_in_lpi_mode_n: 0 irq_tx_path_exit_lpi_mode_n: 0 irq_rx_path_in_lpi_mode_n: 0 irq_rx_path_exit_lpi_mode_n: 0 Regards, Martin [0] http://lists.infradead.org/pipermail/linux-amlogic/2016-November/001674.html