[][CRITICAL][kernel][mt7988][eth][Fix issue of transmitting abnormal data for USXGMII]

[Description]
Fix issue of transmitting abnormal data for USXGMII.

Without this patch, the USXGMII may be transmitting abnormal data because
FIFOs are corrupted.

[Release-log]
N/A


Change-Id: Ic5f51c3f80082087c0e23ad64e770b4be9ef58f7
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/8838029
diff --git a/21.02/files/target/linux/mediatek/files-5.4/drivers/net/ethernet/mediatek/mtk_usxgmii.c b/21.02/files/target/linux/mediatek/files-5.4/drivers/net/ethernet/mediatek/mtk_usxgmii.c
index f114225..7d3f35f 100644
--- a/21.02/files/target/linux/mediatek/files-5.4/drivers/net/ethernet/mediatek/mtk_usxgmii.c
+++ b/21.02/files/target/linux/mediatek/files-5.4/drivers/net/ethernet/mediatek/mtk_usxgmii.c
@@ -187,6 +187,8 @@
 	regmap_update_bits(mpcs->regmap_pextp, 0x0070, GENMASK(31, 0),
 			   0x02002800);
 	ndelay(1020);
+	regmap_update_bits(mpcs->regmap_pextp, 0x3040, GENMASK(31, 0),
+			   0x20000000);
 	/* Setup DA default value */
 	regmap_update_bits(mpcs->regmap_pextp, 0x30B0, GENMASK(31, 0),
 			   0x00000020);
@@ -299,6 +301,8 @@
 	regmap_update_bits(mpcs->regmap_pextp, 0x0070, GENMASK(31, 0),
 			   0x02002800);
 	ndelay(1020);
+	regmap_update_bits(mpcs->regmap_pextp, 0x3040, GENMASK(31, 0),
+			   0x20000000);
 	/* Setup DA default value */
 	regmap_update_bits(mpcs->regmap_pextp, 0x30B0, GENMASK(31, 0),
 			   0x00000020);
@@ -411,6 +415,8 @@
 	regmap_update_bits(mpcs->regmap_pextp, 0x0070, GENMASK(31, 0),
 			   0x02002800);
 	ndelay(1020);
+	regmap_update_bits(mpcs->regmap_pextp, 0x3040, GENMASK(31, 0),
+			   0x20000000);
 	/* Setup DA default value */
 	regmap_update_bits(mpcs->regmap_pextp, 0x30B0, GENMASK(31, 0),
 			   0x00000020);