kernel: copy kernel 4.19 code to 5.4

No changes were done to the patches while coping them. Currently they do
not apply on top of kernel 5.4.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>

1 files changed, 110 insertions, 0 deletions

diff --git a/target/linux/generic/backport-5.4/735-v5.5-net-sfp-allow-sfp-to-probe-slow-to-initialise-GPON-m.patch b/target/linux/generic/backport-5.4/735-v5.5-net-sfp-allow-sfp-to-probe-slow-to-initialise-GPON-m.patch
new file mode 100644
index 0000000000..6cbd0864f7
--- /dev/null
+++ b/target/linux/generic/backport-5.4/735-v5.5-net-sfp-allow-sfp-to-probe-slow-to-initialise-GPON-m.patch
@@ -0,0 +1,110 @@
+From fb56cd08880aff8fb030e684fa4311bef712a499 Mon Sep 17 00:00:00 2001
+From: Russell King <rmk+kernel@armlinux.org.uk>
+Date: Tue, 5 Nov 2019 13:02:30 +0000
+Subject: [PATCH 633/660] net: sfp: allow sfp to probe slow to initialise GPON
+ modules
+
+Some GPON modules (e.g. Huawei MA5671A) take a significant amount of
+time to start responding on the I2C bus, contary to the SFF
+specifications.
+
+Work around this by implementing a two-level timeout strategy, where
+we initially quickly retry for the module, and then use a slower retry
+after we exceed a maximum number of quick attempts.
+
+Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
+---
+ drivers/net/phy/sfp.c | 38 ++++++++++++++++++++++++++++----------
+ 1 file changed, 28 insertions(+), 10 deletions(-)
+
+--- a/drivers/net/phy/sfp.c
++++ b/drivers/net/phy/sfp.c
+@@ -165,9 +165,12 @@ static const enum gpiod_flags gpio_flags
+  * The SFF-8472 specifies t_serial ("Time from power on until module is
+  * ready for data transmission over the two wire serial bus.") as 300ms.
+  */
+-#define T_SERIAL	msecs_to_jiffies(300)
+-#define T_HPOWER_LEVEL	msecs_to_jiffies(300)
+-#define T_PROBE_RETRY	msecs_to_jiffies(100)
++#define T_SERIAL		msecs_to_jiffies(300)
++#define T_HPOWER_LEVEL		msecs_to_jiffies(300)
++#define T_PROBE_RETRY_INIT	msecs_to_jiffies(100)
++#define R_PROBE_RETRY_INIT	10
++#define T_PROBE_RETRY_SLOW	msecs_to_jiffies(5000)
++#define R_PROBE_RETRY_SLOW	12
+ 
+ /* SFP modules appear to always have their PHY configured for bus address
+  * 0x56 (which with mdio-i2c, translates to a PHY address of 22).
+@@ -202,6 +205,8 @@ struct sfp {
+ 	struct delayed_work timeout;
+ 	struct mutex sm_mutex;			/* Protects state machine */
+ 	unsigned char sm_mod_state;
++	unsigned char sm_mod_tries_init;
++	unsigned char sm_mod_tries;
+ 	unsigned char sm_dev_state;
+ 	unsigned short sm_state;
+ 	unsigned int sm_retries;
+@@ -1392,7 +1397,7 @@ static int sfp_sm_mod_hpower(struct sfp
+ 	return 0;
+ }
+ 
+-static int sfp_sm_mod_probe(struct sfp *sfp)
++static int sfp_sm_mod_probe(struct sfp *sfp, bool report)
+ {
+ 	/* SFP module inserted - read I2C data */
+ 	struct sfp_eeprom_id id;
+@@ -1402,7 +1407,8 @@ static int sfp_sm_mod_probe(struct sfp *
+ 
+ 	ret = sfp_read(sfp, false, 0, &id, sizeof(id));
+ 	if (ret < 0) {
+-		dev_err(sfp->dev, "failed to read EEPROM: %d\n", ret);
++		if (report)
++			dev_err(sfp->dev, "failed to read EEPROM: %d\n", ret);
+ 		return -EAGAIN;
+ 	}
+ 
+@@ -1549,8 +1555,11 @@ static void sfp_sm_module(struct sfp *sf
+ 
+ 	switch (sfp->sm_mod_state) {
+ 	default:
+-		if (event == SFP_E_INSERT)
++		if (event == SFP_E_INSERT) {
+ 			sfp_sm_mod_next(sfp, SFP_MOD_PROBE, T_SERIAL);
++			sfp->sm_mod_tries_init = R_PROBE_RETRY_INIT;
++			sfp->sm_mod_tries = R_PROBE_RETRY_SLOW;
++		}
+ 		break;
+ 
+ 	case SFP_MOD_PROBE:
+@@ -1558,10 +1567,19 @@ static void sfp_sm_module(struct sfp *sf
+ 		if (event != SFP_E_TIMEOUT)
+ 			break;
+ 
+-		err = sfp_sm_mod_probe(sfp);
++		err = sfp_sm_mod_probe(sfp, sfp->sm_mod_tries == 1);
+ 		if (err == -EAGAIN) {
+-			sfp_sm_set_timer(sfp, T_PROBE_RETRY);
+-			break;
++			if (sfp->sm_mod_tries_init &&
++			   --sfp->sm_mod_tries_init) {
++				sfp_sm_set_timer(sfp, T_PROBE_RETRY_INIT);
++				break;
++			} else if (sfp->sm_mod_tries && --sfp->sm_mod_tries) {
++				if (sfp->sm_mod_tries == R_PROBE_RETRY_SLOW - 1)
++					dev_warn(sfp->dev,
++						 "please wait, module slow to respond\n");
++				sfp_sm_set_timer(sfp, T_PROBE_RETRY_SLOW);
++				break;
++			}
+ 		}
+ 		if (err < 0) {
+ 			sfp_sm_mod_next(sfp, SFP_MOD_ERROR, 0);
+@@ -1596,7 +1614,7 @@ static void sfp_sm_module(struct sfp *sf
+ 				sfp_module_remove(sfp->sfp_bus);
+ 				sfp_sm_mod_next(sfp, SFP_MOD_ERROR, 0);
+ 			} else {
+-				sfp_sm_set_timer(sfp, T_PROBE_RETRY);
++				sfp_sm_set_timer(sfp, T_PROBE_RETRY_INIT);
+ 			}
+ 			break;
+ 		}