usb: dwc3: meson-g12a: fix shared reset control use

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@baylibre.com>
Reported-by: Jerome Brunet <jbrunet@baylibre.com>
Link: https://lore.kernel.org/r/20211112162827.128319-3-aouledameur@baylibre.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/dwc3/dwc3-meson-g12a.c b/drivers/usb/dwc3/dwc3-meson-g12a.c
index d0f9b7c..bd814df 100644 (file)
--- 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)