On 05/12/2024 16:18, Jakob Unterwurzacher wrote: > During mass manufacturing, we noticed the mmc_rx_crc_error counter, > as reported by "ethtool -S eth0 | grep mmc_rx_crc_error", to increase > above zero during nuttcp speedtests. Most of the time, this did not > affect the achieved speed, but it prompted this investigation. > > Cycling through the rx_delay range on six boards (see table below) of > various ages shows that there is a large good region from 0x12 to 0x35 > where we see zero crc errors on all tested boards. > > The old rx_delay value (0x10) seems to have always been on the edge for > the KSZ9031RNX that is usually placed on Puma. > > Choose "rx_delay = 0x23" to put us smack in the middle of the good > region. This works fine as well with the KSZ9131RNX PHY that was used > for a small number of boards during the COVID chip shortages. > > Board S/N PHY rx_delay good region > --------- --- -------------------- > Puma TT0069903 KSZ9031RNX 0x11 0x35 > Puma TT0157733 KSZ9031RNX 0x11 0x35 > Puma TT0681551 KSZ9031RNX 0x12 0x37 > Puma TT0681156 KSZ9031RNX 0x10 0x38 > Puma 17496030079 KSZ9031RNX 0x10 0x37 (Puma v1.2 from 2017) > Puma TT0681720 KSZ9131RNX 0x02 0x39 (alternative PHY used in very few boards) > > Intersection of good regions = 0x12 0x35 > Middle of good region = 0x23 > > Relates-to: PUMA-111 Drop 3rd party tags. Also you you CC-ed an address, which suggests you do not work on mainline kernel or you do not use get_maintainers.pl/b4/patman. Regardless of the reason, process needs improvement: please rebase and always work on mainline or start using mentioned tools tools, so correct addresses will be used. Best regards, Krzysztof
