Aw: Re: [BUG] MTK SoC Ethernet throughput TX only ~620Mbit/s since 6.2-rc1

[Frank Wunderlich]

Hi,
> Gesendet: Dienstag, 14. März 2023 um 13:47 Uhr
> Von: "Daniel Golle" <daniel at makrotopia.org>
> An: "Felix Fietkau" <nbd at nbd.name>
> Cc: "Frank Wunderlich" <frank-w at public-files.de>, "Mark Lee" <Mark-MC.Lee at mediatek.com>, "Sean Wang" <sean.wang at mediatek.com>, "Lorenzo Bianconi" <lorenzo at kernel.org>, "David S. Miller" <davem at davemloft.net>, "Eric Dumazet" <edumazet at google.com>, "Jakub Kicinski" <kuba at kernel.org>, "Paolo Abeni" <pabeni at redhat.com>, "Matthias Brugger" <matthias.bgg at gmail.com>, "John Crispin" <john at phrozen.org>, "AngeloGioacchino Del Regno" <angelogioacchino.delregno at collabora.com>, netdev at vger.kernel.org, linux-mediatek at lists.infradead.org, linux-arm-kernel at lists.infradead.org
> Betreff: Re: [BUG] MTK SoC Ethernet throughput TX only ~620Mbit/s since 6.2-rc1
>
> Hi Felix,
> 
> On Tue, Mar 14, 2023 at 11:30:53AM +0100, Felix Fietkau wrote:
> > On 07.03.23 19:32, Frank Wunderlich wrote:
> > > Hi,
> > > 
> > > i've noticed that beginning on 6.2-rc1 the throughput on my Bananapi-R2 and Bananapi-R3 goes from 940Mbit/s down do 620Mbit/s since 6.2-rc1.
> > > Only TX (from SBC PoV) is affected, RX is still 940Mbit/s.
> > > 
> > > i bisected this to this commit:
> > > 
> > > f63959c7eec3151c30a2ee0d351827b62e742dcb ("net: ethernet: mtk_eth_soc: implement multi-queue support for per-port queues")
> > > 
> > > Daniel reported me that this is known so far and they need assistance from MTK and i should report it officially.
> > > 
> > > As far as i understand it the commit should fix problems with clients using non-GBE speeds (10/100 Mbit/s) on the Gbit-capable dsa
> > > interfaces (mt753x connected) behind the mac, but now the Gigabit speed is no more reached.
> > > I see no CRC/dropped packets, retransmitts or similar.
> > > 
> > > after reverting the commit above i get 940Mbit like in rx direction, but this will introduce the problems mentioned above so this not a complete fix.
> > I don't have a BPI-R2, but I tested on BPI-R3 and can't reproduce this
> > issue. Do you see it on all ports, or only on specific ones?
> 
> I also can't reproduce this if unsing any of the gigE ports wired via
> MT7531 on the R3. However, I can reproduce the issue if using a 1 GBit/s
> SFP module in slot SFP1 of the R3 (connected directly to GMAC2/eth1).
> 
> Users have reported this also to be a problem also on MT7622 on devices
> directly connecting a PHY (and not using MT7531).
> 
> In all cases, reverting the commit above fixes the issue.


made quick test with 6.3-rc1 on r3 without reverting the patch above and can confirm daniels test

it seems the problem is no more on switch-ports, but on eth1 i have massive packet loss...seems this caused by the same patch because i tested with reverted version and have no issue there.

regards Frank