On Thu, May 24, 2018 at 8:00 PM, Martin Blumenstingl <martin.blumensti...@googlemail.com> wrote: > Hello Jaap, > > On Thu, May 24, 2018 at 12:00 PM, Jaap Buurman <jaapbuur...@gmail.com> wrote: >> Dear all, >> >> I found some additional information in the system log: Thu May 24 >> 11:38:39 2018 kern.err kernel: [83864.729458] eth0: Invalid MTU 1508 >> requested, hw max 1500 >> Digging deeper, this seems like a message that is spawned by a >> function in /net/core.dev.c of the linux kernel: >> >> if (dev->max_mtu > 0 && new_mtu > dev->max_mtu) { >> net_err_ratelimited("%s: Invalid MTU %d requested, hw max %d\n", >> dev->name, new_mtu, dev->max_mtu); >> return -EINVAL; >> } >> >> Is there anybody that happens to know where exactly this max_mtu value >> is set to 1500? For mt7621 devices this should be 2048 (Baby jambo >> frames). >> >> Thank you very much in advance. >> >> Yours sincerely, >> >> Jaap Buurman >> >> On Tue, May 22, 2018 at 3:05 PM, Jaap Buurman <jaapbuur...@gmail.com> wrote: >>> Dear all, >>> >>> The switch to the 4.14 kernel apparently broke the baby jumbo frames >>> support of 2048 bytes that the switch is capable off. I found out that >>> changing the mtu above 1500 via Luci no longer applies properly. >>> Trying to manually change the mtu via ssh also fails: >>> >>> root@LEDE:~# ifconfig eth0 mtu 1508 up >>> ifconfig: SIOCSIFMTU: Invalid argument >>> >>> If there is any additional information that I can supply, please let >>> me know. I am also more than willing to help test potential fixes :) > I *believe* Mathias has a fix for this in his tree (but I'm not sure > if he has the hardware to test it): [0] > maybe you can give it a go and report back? > > > Regards > Martin > > > [0] > https://git.openwrt.org/?p=openwrt/staging/mkresin.git;a=commitdiff;h=cc5f1fe7aa02943f3b39ffbd9dc3b8fcad569c8f
Dear Martin and Mathias, I have compiled and flashed an image from Mathias' tree checked out at the commit linked in Martin's previous message. Unfortunately, I am still seeing the following message in dmesg: [ 243.845159] eth0: Invalid MTU 1508 requested, hw max 1500 If there are additional tests you would like me to run, please do not hesitate to contact me :) Yours sincerely, Jaap Buurman _______________________________________________ openwrt-devel mailing list openwrt-devel@lists.openwrt.org http://lists.infradead.org/mailman/listinfo/openwrt-devel