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

[Roger Quadros]

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.valkei...@ti.com>
Signed-off-by: Roger Quadros <rog...@ti.com>
Tested-by: Tomi Valkeinen <tomi.valkei...@ti.com>
Cc: <sta...@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

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