netdev - [PATCH 1/2] net: mdiobus: reset deassert delay

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Date:   Tue, 28 Jul 2020 11:02:02 +0200
From:   Bruno Thomsen <bruno.thomsen@...il.com>
To:     netdev <netdev@...r.kernel.org>
Cc:     Bruno Thomsen <bruno.thomsen@...il.com>,
        Andrew Lunn <andrew@...n.ch>,
        Fabio Estevam <festevam@...il.com>,
        Florian Fainelli <f.fainelli@...il.com>,
        Russell King - ARM Linux <linux@...linux.org.uk>,
        Heiner Kallweit <hkallweit1@...il.com>,
        Lars Alex Pedersen <laa@...strup.com>,
        Bruno Thomsen <bth@...strup.com>
Subject: [PATCH 1/2] net: mdiobus: reset deassert delay

The current reset logic only has a delay during assert.
This reuses the delay value as deassert delay to ensure
PHYs are ready for commands. Delays are typically needed
when external hardware slows down reset release with a
RC network. This solution does not need any new device
tree bindings.
It also improves handling of long delays (>20ms) by using
the generic fsleep() for selecting appropriate delay
function.

Signed-off-by: Bruno Thomsen <bruno.thomsen@...il.com>
---
 drivers/net/phy/mdio_bus.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index 6ceee82b2839..84d5ab07fe16 100644
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c
@@ -627,8 +627,9 @@ int __mdiobus_register(struct mii_bus *bus, struct module *owner)
 		bus->reset_gpiod = gpiod;
 
 		gpiod_set_value_cansleep(gpiod, 1);
-		udelay(bus->reset_delay_us);
+		fsleep(bus->reset_delay_us);
 		gpiod_set_value_cansleep(gpiod, 0);
+		fsleep(bus->reset_delay_us);
 	}
 
 	if (bus->reset) {

base-commit: 92ed301919932f777713b9172e525674157e983d
-- 
2.26.2