netdev - [PATCH] net: phy: allow for reset line to be tied to a sleepy GPIO controller

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Message-Id: <20191004135332.5746-1-andrea.merello@gmail.com>
Date:   Fri,  4 Oct 2019 15:53:32 +0200
From:   Andrea Merello <andrea.merello@...il.com>
To:     andrew@...n.ch, f.fainelli@...il.com, hkallweit1@...il.com,
        davem@...emloft.net
Cc:     netdev@...r.kernel.org, Andrea Merello <andrea.merello@...il.com>
Subject: [PATCH] net: phy: allow for reset line to be tied to a sleepy GPIO controller

mdio_device_reset() makes use of the atomic-pretending API flavor for
handling the PHY reset GPIO line.

I found no hint that mdio_device_reset() is called from atomic context
and indeed it uses usleep_range() since long time, so I would assume that
it is OK to sleep there.

This patch switch to gpiod_set_value_cansleep() in mdio_device_reset().
This is relevant if e.g. the PHY reset line is tied to a I2C GPIO
controller.

This has been tested on a ZynqMP board running an upstream 4.19 kernel and
then hand-ported on current kernel tree.

Signed-off-by: Andrea Merello <andrea.merello@...il.com>
---
 drivers/net/phy/mdio_device.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/phy/mdio_device.c b/drivers/net/phy/mdio_device.c
index e282600bd83e..c1d345c3cab3 100644
--- a/drivers/net/phy/mdio_device.c
+++ b/drivers/net/phy/mdio_device.c
@@ -121,7 +121,7 @@ void mdio_device_reset(struct mdio_device *mdiodev, int value)
 		return;

 	if (mdiodev->reset_gpio)
-		gpiod_set_value(mdiodev->reset_gpio, value);
+		gpiod_set_value_cansleep(mdiodev->reset_gpio, value);

 	if (mdiodev->reset_ctrl) {
 		if (value)
-- 
2.17.1