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 <aouledam...@baylibre.com>
Reported-by: Jerome Brunet <jbru...@baylibre.com>
---
changes since v1: [1]
* None for this driver

IMPORTANT:
This patchset depends on this patch [2], it adds reset_control_rearm() call
to the reset framework API, it has been approved by the maintainer, and
will be applied to reset/next

There is currently an immutable branch with it [3]

[1]: 
https://lore.kernel.org/lkml/20201113000508.14702-1-aouledam...@baylibre.com/
[2]: 
https://lore.kernel.org/lkml/20201112230043.28987-1-aouledam...@baylibre.com/
[3]: git://git.pengutronix.de/git/pza/linux.git reset/shared-retrigger

 drivers/usb/dwc3/dwc3-meson-g12a.c | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/drivers/usb/dwc3/dwc3-meson-g12a.c 
b/drivers/usb/dwc3/dwc3-meson-g12a.c
index 417e05381b5d..3fec8f591c93 100644
--- a/drivers/usb/dwc3/dwc3-meson-g12a.c
+++ b/drivers/usb/dwc3/dwc3-meson-g12a.c
@@ -750,7 +750,7 @@ 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)
@@ -759,7 +759,7 @@ static int dwc3_meson_g12a_probe(struct platform_device 
*pdev)
        if (priv->vbus) {
                ret = regulator_enable(priv->vbus);
                if (ret)
-                       goto err_disable_clks;
+                       goto err_rearm;
        }
 
        /* Get dr_mode */
@@ -772,13 +772,13 @@ static int dwc3_meson_g12a_probe(struct platform_device 
*pdev)
 
        ret = priv->drvdata->usb_init(priv);
        if (ret)
-               goto err_disable_clks;
+               goto err_rearm;
 
        /* Init PHYs */
        for (i = 0 ; i < PHY_COUNT ; ++i) {
                ret = phy_init(priv->phys[i]);
                if (ret)
-                       goto err_disable_clks;
+                       goto err_rearm;
        }
 
        /* Set PHY Power */
@@ -816,6 +816,9 @@ static int dwc3_meson_g12a_probe(struct platform_device 
*pdev)
        for (i = 0 ; i < PHY_COUNT ; ++i)
                phy_exit(priv->phys[i]);
 
+err_rearm:
+       reset_control_rearm(priv->reset);
+
 err_disable_clks:
        clk_bulk_disable_unprepare(priv->drvdata->num_clks,
                                   priv->drvdata->clks);
@@ -843,6 +846,8 @@ 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);
 
@@ -883,7 +888,7 @@ 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;
 }
@@ -893,7 +898,9 @@ 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)
-- 
2.17.1

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