From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Geis Subject: Re: [PATCH] arm64: dts: rockchip: improve rk3328-roc-cc rgmii performance. Date: Sat, 15 Jun 2019 08:12:36 -0400 Message-ID: <71dc10a5-1024-d849-336e-476d183e5f46@gmail.com> References: <20190607123731.8737-1-pgwipeout@gmail.com> <1559912295.22520.0@gmail.com> <1560547631.1367.4@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1560547631.1367.4@gmail.com> Content-Language: en-US List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: "Leonidas P. Papadakos" Cc: Jose Abreu , devicetree@vger.kernel.org, Heiko Stuebner , linux-rockchip@lists.infradead.org, Rob Herring , Robin Murphy , linux-arm-kernel@lists.infradead.org List-Id: devicetree@vger.kernel.org On 6/14/2019 5:27 PM, Leonidas P. Papadakos wrote: > > >> The big change was actually snps,aal. >> As per the TRM, DMA channels not address aligned have severe >> limitations, if they work at all. >> >> Setting the DMA ops as address aligned fixed my 30mbps TX issue when >> combined with your snps,txpbl = <0x4>. > > Honestly, I don't notice any difference either way with aal. So what > happens without it? If You only use the 0x4 txpbl and having removed > thresh dma mode, (2 things then) do you get bad tx? > > I'm unsure why, but I think there might be small variations in the different boards (Firefly, Libre). On my board (Libre) with just 0x4 txpbl and thresh dma removed I get a whopping 30mbps. Adding aal brought it up to 900 mbps. I also had stability issues on rx, where it would bounce between 200 and 400 mbps, which adding 0x4 rxpbl helped. I still haven't been able to get rx above 400mpbs though. It's definitely the MTU issue, since setting the max mtu to 1496 fixes most problems. I have to wonder if the pl330 in the rk3328 is bugged, since all of the hardware that misbehaves (usb3, mmc, rgmii) require the dma engine. If this works as a valid replacement for thresh dma mode, then I can submit it for merging. I would like a few more people to test it first. Anyone else with a rk3328-roc-cc board that can test this patch?