lkml.org 
[lkml]   [2020]   [Dec]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v2 2/3] usb: dwc3: meson-g12a: fix shared reset control use
Date
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>
---
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-aouledameur@baylibre.com/
[2]: https://lore.kernel.org/lkml/20201112230043.28987-1-aouledameur@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
\
 
 \ /
  Last update: 2020-12-01 20:04    [W:0.103 / U:1.300 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site