From mboxrd@z Thu Jan 1 00:00:00 1970 From: linux@arm.linux.org.uk (Russell King - ARM Linux) Date: Wed, 16 Jul 2014 19:39:04 +0100 Subject: BUG: i.MX6-FEC: broken TCP tx checksumming In-Reply-To: References: <20140716095850.GO21766@n2100.arm.linux.org.uk> Message-ID: <20140716183904.GQ21766@n2100.arm.linux.org.uk> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wed, Jul 16, 2014 at 04:03:21PM +0200, Holger Schurig wrote: > >> So I tried "ethtool -K eth0 tx off" (on the i.MX6 board) and suddenly > >> ssh worked. > > > > That sounds like the hardware IP header checksumming isn't working. Is > > there anything specific to your setup? VLAN maybe? > > No, no games, I just did a normal "ifconfig eth0 192.168.200.199". > > > Which gcc version are you using? > > Currently http://releases.linaro.org/14.04/components/toolchain/binaries/gcc-linaro-arm-linux-gnueabihf-4.8-2014.04_linux.tar.xz > But I could try a different one. I'd consider asking whether you'd send me fec_main.o with and without the wmb() in it, but I'm not sure if I have the time to look at it right now. > > That's a little heavy-weight, but let's use the sledge hammer first... > > The sledge hammer worked! > > Do you want to to find out which of the for wmb() is actually needed? It may be worth checking whether it needs to be wmb(), or whether barrier() will do - in other words, is it the compiler re-ordering the stores, or is it the hardware re-ordering them. -- FTTC broadband for 0.8mile line: currently at 9.5Mbps down 400kbps up according to speedtest.net.