g...@kernel.org writes: > I have been working towards supporting the MT7530 switch as used in the > MediaTek MT7621 SoC. Unlike the MediaTek MT7623 the MT7621 is built around > a dual core MIPS CPU architecture. But underneath it is what appears to > be the same 7530 switch.
Great! Good to see someone pushing this idea forward. > The following 3 patches are more of an RFC than anything. They allow > use of the mt7530 dsa driver on this device - though with some issues > still to resolve. The primary change required is to not use the 7623 > specific clock and regulator setup - none of that applies when using > the 7621 (and maybe other devices?). The other change required is to > set the 7530 MFC register CPU port number and enable bit. > > The unresolved issues I still have appear to be more related to the > MT7621 ethernet driver (drivers/staging/mt7621-eth/*). I am hoping > someone might have some ideas on these. I don't really have any good > documentation on the ethernet devices on the 7621, so I am kind of > working in the dark here. No offense, but the mt7621-eth driver in staging is horrible. What both René and I have had some success with is adapting the mtk_eth_soc driver already in drivers/net/ethernet/mediatek/. Yes, I know this is supposed to be for other SoCs, but the basic design is obviously the same. I have had some success with a first hackish attemt based on OpenWrt. You can find the early tree here, but note that my focus was basically getting one specific MT7621 board up and running: https://github.com/bmork/LEDE/tree/mt7621-with-mainline-eth-driver This patch has most of the necessary changes to enable that driver for MT7621: https://github.com/bmork/LEDE/commit/3293bc63f5461ca1eb0bbc4ed90145335e7e3404 Not a big deal, as you can see. There is of course a reason I didn't submit this here yet: It is by no means finished... But it works. And I have both GMACs working with this driver, which was my primary goal. > 1. TX packets are not getting an IP header checksum via the normal > off-loaded checksumming when in DSA mode. I have to switch off > NETIF_F_IP_CSUM, so the software stack generates the checksum. > That checksum offloading works ok when not using the 7530 DSA driver. Hmm. How do I test this? > 2. Maximal sized RX packets get silently dropped. So receive side packets > that are large (perfect case is the all-but-last packets in a fragemented > larger packet) appear to be dropped at the mt7621 ethernet MAC level. > The 7530 MIB switch register counters show receive packets at the physical > switch port side and at the CPU switch port - but I get no packets > received or errors in the 7621 ethernet MAC. If I set the mtu of the > server at the other end a little smaller (a few bytes is enough) then > I get all the packets through. It seems like the DSA/VLAN tag bytes > are causing a too large packet to get silently dropped somewhere. Are you referring to the configured MTU size or some other maximal size? If MTU, then I don't seem to have this issue with the driver from drivers/net/ethernet/mediatek/. Bjørn
