On Thu, Feb 15, 2018 at 3:32 PM, André Przywara <andre.przyw...@arm.com> wrote: > Hi, > > thanks for picking this up! > > (CC:ing Icenowy, who was engaged in a Linux fix for this issue last year > [2][3]. It's Chinese New Year though, so not sure how quickly she will > answer). > > On 14/02/18 23:02, kev...@freebsd.org wrote: >> The Pine64 has a known issue on gigabit links (see [1]); some boards suffer >> significant packet loss on Gigabit links. > > Do you have a faulty board at hand? What is the actual effect in U-Boot? > IIRC the bug "just" causes a slower connection in Gigabit mode, I am not > sure we care so much in U-Boot? Or is it actually packages dropped, > which is much more annoying without TCP covering up for this?
I do. =) My board in particular sees 60-70% packet loss without this, making netboot incredibly unreliable. > >> This patch sets the magical bits >> in CONFREG on the RTL8211E PHY to turn off the internal delay and do some >> other >> undocumented stuff. > > So if I remember the discussion correctly, this workaround affects the > performance of the "good" boards. Have you checked this? > There was a discussion last year [2][3] about how to fix this in Linux, > which definitely involved some DT property (ideally in the PHY node). > This would allow people to turn this on and off depending on their > particular board. > I am not sure this discussion lead anywhere, though, it might be a good > idea to warm this up again. > Unfortunately, I do not have a good board to test with, so I've no idea what it ends up doing to performance. for them. I think rgmii-txid is actually not right for this. As an aside, I've pulled this value from [1]. The value they ended up going with (as seen in this patch and in [1]) turns off both TXID and RXID (IIRC, from the realtek documentation for this PHY), leaving us with just plain ol' "rgmii" with no internal delay at all. [1] also applies it unconditionally for pine64. [1] https://github.com/longsleep/linux-pine64/commit/ffe3ca5be7682bbeb0fdadede29acd4a3c888015 _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot