[PATCH] mfd: omap-usb-tll: Don't hold lock during pm_runtime_get/put_sync()

From: Roger Quadros
Date: Wed Dec 18 2013 - 05:02:09 EST


pm_runtime_get/put_sync() can sleep so don't hold spinlock while
calling them.

This patch prevents a BUG() when CONFIG_DEBUG_ATOMIC_SLEEP is enabled.
Bug is present in Kernel versions v3.9 onwards.

Reported-by: Tomi Valkeinen <tomi.valkeinen@xxxxxx>
Signed-off-by: Roger Quadros <rogerq@xxxxxx>
Tested-by: Tomi Valkeinen <tomi.valkeinen@xxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> # 3.9+
---
drivers/mfd/omap-usb-tll.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/mfd/omap-usb-tll.c b/drivers/mfd/omap-usb-tll.c
index 0d946ae1..248004c 100644
--- a/drivers/mfd/omap-usb-tll.c
+++ b/drivers/mfd/omap-usb-tll.c
@@ -346,7 +346,9 @@ int omap_tll_init(struct usbhs_omap_platform_data *pdata)
for (i = 0; i < tll->nch; i++)
needs_tll |= omap_usb_mode_needs_tll(pdata->port_mode[i]);

+ spin_unlock(&tll_lock);
pm_runtime_get_sync(tll_dev);
+ spin_lock(&tll_lock);

if (needs_tll) {
void __iomem *base = tll->base;
@@ -398,9 +400,8 @@ int omap_tll_init(struct usbhs_omap_platform_data *pdata)
}
}

- pm_runtime_put_sync(tll_dev);
-
spin_unlock(&tll_lock);
+ pm_runtime_put_sync(tll_dev);

return 0;
}
@@ -420,7 +421,9 @@ int omap_tll_enable(struct usbhs_omap_platform_data *pdata)

tll = dev_get_drvdata(tll_dev);

+ spin_unlock(&tll_lock);
pm_runtime_get_sync(tll_dev);
+ spin_lock(&tll_lock);

for (i = 0; i < tll->nch; i++) {
if (omap_usb_mode_needs_tll(pdata->port_mode[i])) {
@@ -438,7 +441,6 @@ int omap_tll_enable(struct usbhs_omap_platform_data *pdata)
}

spin_unlock(&tll_lock);
-
return 0;
}
EXPORT_SYMBOL_GPL(omap_tll_enable);
@@ -464,9 +466,8 @@ int omap_tll_disable(struct usbhs_omap_platform_data *pdata)
}
}

- pm_runtime_put_sync(tll_dev);
-
spin_unlock(&tll_lock);
+ pm_runtime_put_sync(tll_dev);

return 0;
}
--
1.8.3.2

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