[PATCH v2] mfd: omap-usb-tll: Don't hold lock during pm_runtime_get/put_sync()

Roger Quadros
2014-01-08T07:15:49Z

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

This patch prevents a BUG() during system suspend when
CONFIG_DEBUG_ATOMIC_SLEEP is enabled.

Bug is present in Kernel versions v3.9 onwards.

Reported-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: Roger Quadros <rogerq@ti.com>
Tested-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: <stable@vger.kernel.org> # 3.9+
---
drivers/mfd/omap-usb-tll.c | 36 ++++++++++++------------------------
1 file changed, 12 insertions(+), 24 deletions(-)

diff --git a/drivers/mfd/omap-usb-tll.c b/drivers/mfd/omap-usb-tll.c
index 0d946ae1..c409be9 100644
--- a/drivers/mfd/omap-usb-tll.c
+++ b/drivers/mfd/omap-usb-tll.c
@@ -333,21 +333,17 @@ int omap_tll_init(struct usbhs_omap_platform_data *pdata)
unsigned reg;
struct usbtll_omap *tll;

- spin_lock(&tll_lock);
-
- if (!tll_dev) {
- spin_unlock(&tll_lock);
+ if (!tll_dev)
return -ENODEV;
- }

- tll = dev_get_drvdata(tll_dev);
+ pm_runtime_get_sync(tll_dev);

+ spin_lock(&tll_lock);
+ tll = dev_get_drvdata(tll_dev);
needs_tll = false;
for (i = 0; i < tll->nch; i++)
needs_tll |= omap_usb_mode_needs_tll(pdata->port_mode[i]);

- pm_runtime_get_sync(tll_dev);
-
if (needs_tll) {
void __iomem *base = tll->base;

@@ -398,9 +394,8 @@ 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;
}
@@ -411,17 +406,14 @@ int omap_tll_enable(struct usbhs_omap_platform_data *pdata)
int i;
struct usbtll_omap *tll;

- spin_lock(&tll_lock);
-
- if (!tll_dev) {
- spin_unlock(&tll_lock);
+ if (!tll_dev)
return -ENODEV;
- }
-
- tll = dev_get_drvdata(tll_dev);

pm_runtime_get_sync(tll_dev);

+ spin_lock(&tll_lock);
+ tll = dev_get_drvdata(tll_dev);
+
for (i = 0; i < tll->nch; i++) {
if (omap_usb_mode_needs_tll(pdata->port_mode[i])) {
int r;
@@ -448,13 +440,10 @@ int omap_tll_disable(struct usbhs_omap_platform_data *pdata)
int i;
struct usbtll_omap *tll;

- spin_lock(&tll_lock);
-
- if (!tll_dev) {
- spin_unlock(&tll_lock);
+ if (!tll_dev)
return -ENODEV;
- }

+ spin_lock(&tll_lock);
tll = dev_get_drvdata(tll_dev);

for (i = 0; i < tll->nch; i++) {
@@ -464,9 +453,8 @@ 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