[PATCH 5.16 0566/1039] usb: dwc3: meson-g12a: fix shared reset control use

From: Greg Kroah-Hartman
Date: Mon Jan 24 2022 - 16:57:44 EST


From: Amjad Ouled-Ameur <aouledameur@xxxxxxxxxxxx>

[ Upstream commit 4ce3b45704d5ef46fb4b28083c8aba6716fabf3b ]

reset_control_(de)assert() calls are called on a shared reset line when
reset_control_reset has been used. This is not allowed by the reset
framework.

Use reset_control_rearm() call in suspend() and remove() as a way to state
that the resource is no longer used, hence the shared reset line
may be triggered again by other devices. Use reset_control_rearm() also in
case probe fails after reset() has been called.

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@xxxxxxxxxxxx>
Reported-by: Jerome Brunet <jbrunet@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20211112162827.128319-3-aouledameur@xxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/usb/dwc3/dwc3-meson-g12a.c | 17 ++++++++++++-----
1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/drivers/usb/dwc3/dwc3-meson-g12a.c b/drivers/usb/dwc3/dwc3-meson-g12a.c
index d0f9b7c296b0d..bd814df3bf8b8 100644
--- a/drivers/usb/dwc3/dwc3-meson-g12a.c
+++ b/drivers/usb/dwc3/dwc3-meson-g12a.c
@@ -755,16 +755,16 @@ static int dwc3_meson_g12a_probe(struct platform_device *pdev)

ret = dwc3_meson_g12a_get_phys(priv);
if (ret)
- goto err_disable_clks;
+ goto err_rearm;

ret = priv->drvdata->setup_regmaps(priv, base);
if (ret)
- goto err_disable_clks;
+ goto err_rearm;

if (priv->vbus) {
ret = regulator_enable(priv->vbus);
if (ret)
- goto err_disable_clks;
+ goto err_rearm;
}

/* Get dr_mode */
@@ -825,6 +825,9 @@ err_disable_regulator:
if (priv->vbus)
regulator_disable(priv->vbus);

+err_rearm:
+ reset_control_rearm(priv->reset);
+
err_disable_clks:
clk_bulk_disable_unprepare(priv->drvdata->num_clks,
priv->drvdata->clks);
@@ -852,6 +855,8 @@ static int dwc3_meson_g12a_remove(struct platform_device *pdev)
pm_runtime_put_noidle(dev);
pm_runtime_set_suspended(dev);

+ reset_control_rearm(priv->reset);
+
clk_bulk_disable_unprepare(priv->drvdata->num_clks,
priv->drvdata->clks);

@@ -892,7 +897,7 @@ static int __maybe_unused dwc3_meson_g12a_suspend(struct device *dev)
phy_exit(priv->phys[i]);
}

- reset_control_assert(priv->reset);
+ reset_control_rearm(priv->reset);

return 0;
}
@@ -902,7 +907,9 @@ static int __maybe_unused dwc3_meson_g12a_resume(struct device *dev)
struct dwc3_meson_g12a *priv = dev_get_drvdata(dev);
int i, ret;

- reset_control_deassert(priv->reset);
+ ret = reset_control_reset(priv->reset);
+ if (ret)
+ return ret;

ret = priv->drvdata->usb_init(priv);
if (ret)
--
2.34.1