Am Mittwoch, 13. März 2019, 19:45:36 CET schrieb Peter Geis: > Resubmitting, after further research, review, comments, and suggestions. > > Several rk3328 based boards experience high rgmii tx error rates. > This is due to several pins in the rk3328.dtsi rgmii pinmux that are > missing a defined pull strength setting. > This causes the pinmux driver to default to 2ma (bit mask 00). > > These pins are only defined in the rk3328.dtsi, and are not listed in > the rk3328 specification. > The TRM only lists them as "Reserved" > (RK3328 TRM V1.1, 3.3.3 Detail Register Description, GRF_GPIO0B_IOMUX, > GRF_GPIO0C_IOMUX, GRF_GPIO0D_IOMUX). > However, removal of these pins from the rgmii pinmux definition causes > the interface to fail to transmit. > > Also, the rgmii tx and rx pins defined in the dtsi are not consistent > with the rk3328 specification, with tx pins currently set to 12ma and > rx pins set to 2ma. > > Fix this by setting tx pins to 8ma and the rx pins to 4ma, consistent > with the specification. > Defining the drive strength for the undefined pins eliminated the high > tx packet error rate observed under heavy data transfers. > Aligning the drive strength to the TRM values eliminated the occasional > packet retry errors under iperf3 testing. > This allows much higher data rates with no recorded tx errors. > > Tested on the rk3328-roc-cc board. > > Signed-off-by: Peter Geis <pgwipeout@xxxxxxxxx> applied as fix for 5.1 after adding Fixes and Cc-stable-tags Thanks Heiko _______________________________________________ Linux-rockchip mailing list Linux-rockchip@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/linux-rockchip
