From: Felipe Balbi <[email protected]>

3.12-stable review patch.  If anyone has any objections, please let me know.

===============

commit 3e43a0725637299a14369e3ef109c25a8ec5c008 upstream.

We need a pm_runtime_get_sync() call from
within musb_gadget_pullup() to make sure
registers are accessible at that time.

The problem is that musb_gadget_pullup() is
called with IRQs disabled and, because of that,
we need to tell pm_runtime that this pm_runtime_get_sync()
is IRQ safe.

We can simply add pm_runtime_irq_safe(), however, because
we need to make our read/write accessor function pointers
have been initialized before trying to use them. This means
that all pm_runtime initialization for musb_core needs to
be moved down so that when we call pm_runtime_irq_safe(),
the pm_runtime_get_sync() that it calls on the parent, won't
cause a crash due to NULL musb_read/write accessors.

Reported-by: Pali Rohár <[email protected]>
Signed-off-by: Felipe Balbi <[email protected]>
Signed-off-by: Jiri Slaby <[email protected]>
---
 drivers/usb/musb/musb_core.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
index 2cca870d9762..7c0c9335a0d9 100644
--- a/drivers/usb/musb/musb_core.c
+++ b/drivers/usb/musb/musb_core.c
@@ -1843,16 +1843,18 @@ musb_init_controller(struct device *dev, int nIrq, void 
__iomem *ctrl)
                goto fail0;
        }
 
-       pm_runtime_use_autosuspend(musb->controller);
-       pm_runtime_set_autosuspend_delay(musb->controller, 200);
-       pm_runtime_enable(musb->controller);
-
        spin_lock_init(&musb->lock);
        musb->board_set_power = plat->set_power;
        musb->min_power = plat->min_power;
        musb->ops = plat->platform_ops;
        musb->port_mode = plat->mode;
 
+       /* We need musb_read/write functions initialized for PM */
+       pm_runtime_use_autosuspend(musb->controller);
+       pm_runtime_set_autosuspend_delay(musb->controller, 200);
+       pm_runtime_irq_safe(musb->controller);
+       pm_runtime_enable(musb->controller);
+
        /* The musb_platform_init() call:
         *   - adjusts musb->mregs
         *   - sets the musb->isr
-- 
2.3.0

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