Merge branch 'rework-sfp-a2-access-conditionals'

Russell King says:

====================
Rework SFP A2 access conditionals

This series reworks the SFP A2 (diagnostics and control) access so we
don't end up testing a variable number of conditions in several places.

This also resolves a minor issue where we may have a module indicating
that it is not SFF8472 compliant, doesn't implement A2, but fails to
set the enhanced option byte to zero, leading to accesses to the A2
page that fail.

The first patch adds a new flag "have_a2" which indicates whether we
should be accessing the A2 page, and uses this for hwmon. The
conditions are kept the same.

The second patch extends the check for soft-state polling and control
by using this "have_a2" flag (which effectively augments the check to
include some level of SFF8472 compliance.)
====================

Link: https://lore.kernel.org/r/ZAoBnqGBnIZzLwpV@shell.armlinux.org.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: kuba-moo

drivers/net/phy/sfp.c

@@ -255,6 +255,8 @@ struct sfp {
 	unsigned int module_power_mW;
 	unsigned int module_t_start_up;
 	unsigned int module_t_wait;
+
+	bool have_a2;
 	bool tx_fault_ignore;
 
 	const struct sfp_quirk *quirk;
@@ -1453,20 +1455,10 @@ static void sfp_hwmon_probe(struct work_struct *work)
 
 static int sfp_hwmon_insert(struct sfp *sfp)
 {
-	if (sfp->id.ext.sff8472_compliance == SFP_SFF8472_COMPLIANCE_NONE)
-		return 0;
-
-	if (!(sfp->id.ext.diagmon & SFP_DIAGMON_DDM))
-		return 0;
-
-	if (sfp->id.ext.diagmon & SFP_DIAGMON_ADDRMODE)
-		/* This driver in general does not support address
-		 * change.
-		 */
-		return 0;
-
-	mod_delayed_work(system_wq, &sfp->hwmon_probe, 1);
-	sfp->hwmon_tries = R_PROBE_RETRY_SLOW;
+	if (sfp->have_a2 && sfp->id.ext.diagmon & SFP_DIAGMON_DDM) {
+		mod_delayed_work(system_wq, &sfp->hwmon_probe, 1);
+		sfp->hwmon_tries = R_PROBE_RETRY_SLOW;
+	}
 
 	return 0;
 }
@@ -1916,6 +1908,18 @@ static int sfp_cotsworks_fixup_check(struct sfp *sfp, struct sfp_eeprom_id *id)
 	return 0;
 }
 
+static int sfp_module_parse_sff8472(struct sfp *sfp)
+{
+	/* If the module requires address swap mode, warn about it */
+	if (sfp->id.ext.diagmon & SFP_DIAGMON_ADDRMODE)
+		dev_warn(sfp->dev,
+			 "module address swap to access page 0xA2 is not supported.\n");
+	else
+		sfp->have_a2 = true;
+
+	return 0;
+}
+
 static int sfp_sm_mod_probe(struct sfp *sfp, bool report)
 {
 	/* SFP module inserted - read I2C data */
@@ -2053,10 +2057,11 @@ static int sfp_sm_mod_probe(struct sfp *sfp, bool report)
 		return -EINVAL;
 	}
 
-	/* If the module requires address swap mode, warn about it */
-	if (sfp->id.ext.diagmon & SFP_DIAGMON_ADDRMODE)
-		dev_warn(sfp->dev,
-			 "module address swap to access page 0xA2 is not supported.\n");
+	if (sfp->id.ext.sff8472_compliance != SFP_SFF8472_COMPLIANCE_NONE) {
+		ret = sfp_module_parse_sff8472(sfp);
+		if (ret < 0)
+			return ret;
+	}
 
 	/* Parse the module power requirement */
 	ret = sfp_module_parse_power(sfp);
@@ -2103,6 +2108,7 @@ static void sfp_sm_mod_remove(struct sfp *sfp)
 
 	memset(&sfp->id, 0, sizeof(sfp->id));
 	sfp->module_power_mW = 0;
+	sfp->have_a2 = false;
 
 	dev_info(sfp->dev, "module removed\n");
 }
@@ -2278,7 +2284,11 @@ static void sfp_sm_main(struct sfp *sfp, unsigned int event)
 		    sfp->sm_dev_state != SFP_DEV_UP)
 			break;
 
-		if (!(sfp->id.ext.diagmon & SFP_DIAGMON_ADDRMODE))
+		/* Only use the soft state bits if we have access to the A2h
+		 * memory, which implies that we have some level of SFF-8472
+		 * compliance.
+		 */
+		if (sfp->have_a2)
 			sfp_soft_start_poll(sfp);
 
 		sfp_module_tx_enable(sfp);