kernel: add pending mtk_sgmii and phy improvements from @lynxis

Add pending patches from Alexander 'lynxis' Couzens which are required
for RealTek NBase-T PHYs or SFP+ cages to work when connected to the
SGMII interface provided by recent MediaTek SoCs [1].
The patches for MT753x fix link speed limitation on CPU ports observed
by many users which is due to reset being carried out wrongly [2].

[1]: https://patchwork.kernel.org/project/netdevbpf/list/?series=669488&state=*
[2]: https://patchwork.kernel.org/project/netdevbpf/list/?series=669486&state=*

Signed-off-by: Daniel Golle <daniel@makrotopia.org>

1 files changed, 28 insertions, 0 deletions

diff --git a/target/linux/generic/pending-5.15/723-net-mt7531-ensure-all-MACs-are-powered-down-before-r.patch b/target/linux/generic/pending-5.15/723-net-mt7531-ensure-all-MACs-are-powered-down-before-r.patch
new file mode 100644
index 0000000000..cc12d72110
--- /dev/null
+++ b/target/linux/generic/pending-5.15/723-net-mt7531-ensure-all-MACs-are-powered-down-before-r.patch
@@ -0,0 +1,28 @@
+From 3fb8841513c4ec3a2e5d366df86230c45f239a57 Mon Sep 17 00:00:00 2001
+From: Alexander Couzens <lynxis@fe80.eu>
+Date: Sat, 13 Aug 2022 13:08:22 +0200
+Subject: [PATCH 03/10] net: mt7531: ensure all MACs are powered down before
+ reset
+
+The datasheet [1] explicit describes it as requirement for a reset.
+
+[1] MT7531 Reference Manual for Development Board rev 1.0, page 735
+
+Signed-off-by: Alexander Couzens <lynxis@fe80.eu>
+---
+ drivers/net/dsa/mt7530.c | 4 ++++
+ 1 file changed, 4 insertions(+)
+
+--- a/drivers/net/dsa/mt7530.c
++++ b/drivers/net/dsa/mt7530.c
+@@ -2324,6 +2324,10 @@ mt7531_setup(struct dsa_switch *ds)
+ 		return -ENODEV;
+ 	}
+ 
++	/* all MACs must be forced link-down before sw reset */
++	for (i = 0; i < MT7530_NUM_PORTS; i++)
++		mt7530_write(priv, MT7530_PMCR_P(i), MT7531_FORCE_LNK);
++
+ 	/* Reset the switch through internal reset */
+ 	mt7530_write(priv, MT7530_SYS_CTRL,
+ 		     SYS_CTRL_PHY_RST | SYS_CTRL_SW_RST |