Hi Sunil, > Olimex team working with FreedomBox team have noticed a significant > slowdown in Gigabit Ethernet when transmitting. Original report from > Olimex team is attached. This is applicable for hardware Rev.G2 of the > A20 OLinuXino Lime2 board.
It seems you forgot to attach the mentioned Olimex report. Do I understand you correctly that the attached patch is what Olimex propose but that you do *not* recommended to use it as-is because it badly affects older boards? Were your Lime2 boards connected with a cross-over cable or via a switch during those tests? I am no expert on these things, but did some digging...: Older Lime2 use RTL8211CL-GR and Rev.G onwards use RTL8211E-VB-CG1, according to https://github.com/OLIMEX/OLINUXINO/tree/master/HARDWARE/A20-OLinuXino-LIME2 Lime2 RTL8211C has a buggy PLL, and u-boot since 2016.11+dfsg1-2 force RTL8211C (but *not* RTL8211E) to run as master when in gigabit mode, according to u-boot commit cebf3f5 Upstream discussion and tests when introducing CONFIG_GMAC_TX_DELAY: https://lists.denx.de/pipermail/u-boot/2016-March/248498.html Above upstream tests most likely used only the older RTL8211C PHY, as rev.G was seemingly introduced mid 2016 at earliest, according to https://olimex.wordpress.com/2016/12/08/a20-olinuxino-lime2-now-with-pcb-revision-g/ and https://olimex.wordpress.com/2016/05/04/lime2-get-better-now-with-emmc-flash-a20-olinuxino-lime2-emmc/ and (vaguely) https://github.com/OLIMEX/OLINUXINO/blob/master/HARDWARE/A20-OLinuXino-LIME2/hardware_revision_changes_log.txt#L61 - Jonas -- * Jonas Smedegaard - idealist & Internet-arkitekt * Tlf.: +45 40843136 Website: http://dr.jones.dk/ [x] quote me freely [ ] ask before reusing [ ] keep private
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