net: stmmac: dwmac-meson8b: fix the RX delay validation

When has_prg_eth1_rgmii_rx_delay is true then we support RX delays
between 0ps and 3000ps in 200ps steps. Swap the validation of the RX
delay based on the has_prg_eth1_rgmii_rx_delay flag so the 200ps check
is now applied correctly on G12A SoCs (instead of only allow 0ps or
2000ps on G12A, but 0..3000ps in 200ps steps on older SoCs which don't
support that).

Fixes: de94fc10 ("net: stmmac: dwmac-meson8b: add support for the RGMII RX delay on G12A")
Reported-by: NMartijn van Deventer <martijn@martijnvandeventer.nl>
Signed-off-by: NMartin Blumenstingl <martin.blumenstingl@googlemail.com>
Link: https://lore.kernel.org/r/20210119202424.591349-1-martin.blumenstingl@googlemail.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/stmicro/stmmac/dwmac-meson8b.c

@@ -443,16 +443,16 @@ static int meson8b_dwmac_probe(struct platform_device *pdev)
 	}
 
 	if (dwmac->data->has_prg_eth1_rgmii_rx_delay) {
-		if (dwmac->rx_delay_ps != 0 && dwmac->rx_delay_ps != 2000) {
+		if (dwmac->rx_delay_ps > 3000 || dwmac->rx_delay_ps % 200) {
 			dev_err(dwmac->dev,
-				"The only allowed RGMII RX delays values are: 0ps, 2000ps");
+				"The RGMII RX delay range is 0..3000ps in 200ps steps");
 			ret = -EINVAL;
 			goto err_remove_config_dt;
 		}
 	} else {
-		if (dwmac->rx_delay_ps > 3000 || dwmac->rx_delay_ps % 200) {
+		if (dwmac->rx_delay_ps != 0 && dwmac->rx_delay_ps != 2000) {
 			dev_err(dwmac->dev,
-				"The RGMII RX delay range is 0..3000ps in 200ps steps");
+				"The only allowed RGMII RX delays values are: 0ps, 2000ps");
 			ret = -EINVAL;
 			goto err_remove_config_dt;
 		}