bcm47xx: fix bgmac regression present in 5.4 kernel

This fixes:
[    2.548098] bgmac_bcma bcma0:1: Failed to register fixed PHY device
[    2.554584] bgmac_bcma bcma0:1: Cannot connect to phy
and downstream (swconfig-based) b53 driver failing to load.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
(cherry picked from commit 6cdac994012003065a7040ceba3186f80db3cdbe)

diff --git a/target/linux/bcm47xx/patches-5.4/700-net-bgmac-connect-to-PHY-even-if-it-is-BGMAC_PHY_NOR.patch b/target/linux/bcm47xx/patches-5.4/700-net-bgmac-connect-to-PHY-even-if-it-is-BGMAC_PHY_NOR.patch
new file mode 100644 (file)
index 0000000..2fcfbb7
--- /dev/null
+++ b/target/linux/bcm47xx/patches-5.4/700-net-bgmac-connect-to-PHY-even-if-it-is-BGMAC_PHY_NOR.patch
@@ -0,0 +1,42 @@
+From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl>
+Date: Sun, 7 Nov 2021 14:20:40 +0100
+Subject: [PATCH] net: bgmac: connect to PHY even if it is BGMAC_PHY_NOREGS
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+Recent bgmac change was meant to just fix a race between "Generic PHY"
+and "bcm53xx" drivers after -EPROBE_DEFER. It modified bgmac to use
+phy_connect() only if there is a real PHY device connected.
+
+That change broke bgmac on bcm47xx. bcma_phy_connect() now registers a
+fixed PHY with the bgmac_phy_connect_direct(). That fails as another
+fixed PHY (also using address 0) is already registered - by bcm47xx arch
+code bcm47xx_register_bus_complete().
+
+This change brings origial behaviour. It connects Ethernet interface
+with pseudo-PHY (switch device) and adjusts Ethernet interface link to
+match connected switch.
+
+This fixes:
+[    2.548098] bgmac_bcma bcma0:1: Failed to register fixed PHY device
+[    2.554584] bgmac_bcma bcma0:1: Cannot connect to phy
+
+Fixes: b5375509184d ("net: bgmac: improve handling PHY")
+Link: https://lore.kernel.org/netdev/3639116e-9292-03ca-b9d9-d741118a4541@gmail.com/T/#u
+Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
+---
+ drivers/net/ethernet/broadcom/bgmac-bcma.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/drivers/net/ethernet/broadcom/bgmac-bcma.c
++++ b/drivers/net/ethernet/broadcom/bgmac-bcma.c
+@@ -94,7 +94,7 @@ static int bcma_phy_connect(struct bgmac
+               return 0;
+ 
+       /* Connect to the PHY */
+-      if (bgmac->mii_bus && bgmac->phyaddr != BGMAC_PHY_NOREGS) {
++      if (bgmac->mii_bus) {
+               snprintf(bus_id, sizeof(bus_id), PHY_ID_FMT, bgmac->mii_bus->id,
+                        bgmac->phyaddr);
+               phy_dev = phy_connect(bgmac->net_dev, bus_id, bgmac_adjust_link,