[PATCH v6 3/3] phy: amlogic: meson8b-usb2: fix shared reset control use

Amjad Ouled-Ameur
2022-01-11T09:53:35Z

Use reset_control_rearm() call if an error occurs in case
phy_meson8b_usb2_power_on() fails after reset() has been called, or in
case phy_meson8b_usb2_power_off() is called i.e the resource is no longer
used and the reset line may be triggered again by other devices.

reset_control_rearm() keeps use of triggered_count sane in the reset
framework, use of reset_control_reset() on shared reset line should
be balanced with reset_control_rearm().

Signed-off-by: Amjad Ouled-Ameur <aouledameur@baylibre.com>
Reported-by: Jerome Brunet <jbrunet@baylibre.com>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
---
drivers/phy/amlogic/phy-meson8b-usb2.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/drivers/phy/amlogic/phy-meson8b-usb2.c b/drivers/phy/amlogic/phy-meson8b-usb2.c
index 77e7e9b1428c..dd96763911b8 100644
--- a/drivers/phy/amlogic/phy-meson8b-usb2.c
+++ b/drivers/phy/amlogic/phy-meson8b-usb2.c
@@ -154,6 +154,7 @@ static int phy_meson8b_usb2_power_on(struct phy *phy)
ret = clk_prepare_enable(priv->clk_usb_general);
if (ret) {
dev_err(&phy->dev, "Failed to enable USB general clock\n");
+ reset_control_rearm(priv->reset);
return ret;
}

@@ -161,6 +162,7 @@ static int phy_meson8b_usb2_power_on(struct phy *phy)
if (ret) {
dev_err(&phy->dev, "Failed to enable USB DDR clock\n");
clk_disable_unprepare(priv->clk_usb_general);
+ reset_control_rearm(priv->reset);
return ret;
}

@@ -199,6 +201,7 @@ static int phy_meson8b_usb2_power_on(struct phy *phy)
dev_warn(&phy->dev, "USB ID detect failed!\n");
clk_disable_unprepare(priv->clk_usb);
clk_disable_unprepare(priv->clk_usb_general);
+ reset_control_rearm(priv->reset);
return -EINVAL;
}
}
@@ -218,6 +221,7 @@ static int phy_meson8b_usb2_power_off(struct phy *phy)

clk_disable_unprepare(priv->clk_usb);
clk_disable_unprepare(priv->clk_usb_general);
+ reset_control_rearm(priv->reset);

/* power off the PHY by putting it into reset mode */
regmap_update_bits(priv->regmap, REG_CTRL, REG_CTRL_POWER_ON_RESET,
--
2.25.1