kernel: sfp: re-attempt probing for phy

Add patches retrying to probe the PHY to restore support for PHYs taking
longer to initialize without breaking modules without PHYs.

Patches taken from http://git.armlinux.org.uk/cgit/linux-arm.git/log/?h=phy

Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>

1 files changed, 97 insertions, 0 deletions

diff --git a/target/linux/generic/pending-4.19/758-net-sfp-error-handling-for-phy-probe.patch b/target/linux/generic/pending-4.19/758-net-sfp-error-handling-for-phy-probe.patch
new file mode 100644
index 0000000000..00896dfa26
--- /dev/null
+++ b/target/linux/generic/pending-4.19/758-net-sfp-error-handling-for-phy-probe.patch
@@ -0,0 +1,97 @@
+From 1fba543dc8edf4a43bff3276306648bb27c1e207 Mon Sep 17 00:00:00 2001
+From: Russell King <rmk+kernel@armlinux.org.uk>
+Date: Fri, 29 Nov 2019 00:30:08 +0000
+Subject: [PATCH 3/4] net: sfp: error handling for phy probe
+
+Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
+---
+ drivers/net/phy/sfp.c | 26 +++++++++++++++++---------
+ 1 file changed, 17 insertions(+), 9 deletions(-)
+
+--- a/drivers/net/phy/sfp.c
++++ b/drivers/net/phy/sfp.c
+@@ -1334,7 +1334,7 @@ static void sfp_sm_phy_detach(struct sfp
+ 	sfp->mod_phy = NULL;
+ }
+ 
+-static void sfp_sm_probe_phy(struct sfp *sfp, bool is_c45)
++static int sfp_sm_probe_phy(struct sfp *sfp, bool is_c45)
+ {
+ 	struct phy_device *phy;
+ 	int err;
+@@ -1342,18 +1342,18 @@ static void sfp_sm_probe_phy(struct sfp
+ 	phy = get_phy_device(sfp->i2c_mii, SFP_PHY_ADDR, is_c45);
+ 	if (phy == ERR_PTR(-ENODEV)) {
+ 		dev_info(sfp->dev, "no PHY detected\n");
+-		return;
++		return 0;
+ 	}
+ 	if (IS_ERR(phy)) {
+ 		dev_err(sfp->dev, "mdiobus scan returned %ld\n", PTR_ERR(phy));
+-		return;
++		return PTR_ERR(phy);
+ 	}
+ 
+ 	err = phy_device_register(phy);
+ 	if (err) {
+ 		phy_device_free(phy);
+ 		dev_err(sfp->dev, "phy_device_register failed: %d\n", err);
+-		return;
++		return err;
+ 	}
+ 
+ 	err = sfp_add_phy(sfp->sfp_bus, phy);
+@@ -1361,10 +1361,12 @@ static void sfp_sm_probe_phy(struct sfp
+ 		phy_device_remove(phy);
+ 		phy_device_free(phy);
+ 		dev_err(sfp->dev, "sfp_add_phy failed: %d\n", err);
+-		return;
++		return err;
+ 	}
+ 
+ 	sfp->mod_phy = phy;
++
++	return 0;
+ }
+ 
+ static void sfp_sm_link_up(struct sfp *sfp)
+@@ -1437,21 +1439,24 @@ static void sfp_sm_fault(struct sfp *sfp
+  * Clause 45 copper SFP+ modules (10G) appear to switch their interface
+  * mode according to the negotiated line speed.
+  */
+-static void sfp_sm_probe_for_phy(struct sfp *sfp)
++static int sfp_sm_probe_for_phy(struct sfp *sfp)
+ {
++	int err = 0;
++
+ 	switch (sfp->id.base.extended_cc) {
+ 	case SFF8024_ECC_10GBASE_T_SFI:
+ 	case SFF8024_ECC_10GBASE_T_SR:
+ 	case SFF8024_ECC_5GBASE_T:
+ 	case SFF8024_ECC_2_5GBASE_T:
+-		sfp_sm_probe_phy(sfp, true);
++		err = sfp_sm_probe_phy(sfp, true);
+ 		break;
+ 
+ 	default:
+ 		if (sfp->id.base.e1000_base_t)
+-			sfp_sm_probe_phy(sfp, false);
++			err = sfp_sm_probe_phy(sfp, false);
+ 		break;
+ 	}
++	return err;
+ }
+ 
+ static int sfp_module_parse_power(struct sfp *sfp)
+@@ -1855,7 +1860,10 @@ static void sfp_sm_main(struct sfp *sfp,
+ 	init_done:	/* TX_FAULT deasserted or we timed out with TX_FAULT
+ 			 * clear.  Probe for the PHY and check the LOS state.
+ 			 */
+-			sfp_sm_probe_for_phy(sfp);
++			if (sfp_sm_probe_for_phy(sfp)) {
++				sfp_sm_next(sfp, SFP_S_FAIL, 0);
++				break;
++			}
+ 			if (sfp_module_start(sfp->sfp_bus)) {
+ 				sfp_sm_next(sfp, SFP_S_FAIL, 0);
+ 				break;