[PATCH 3.12 137/175] usb: musb: core: add pm_runtime_irq_safe()

From: Jiri Slaby
Date: Tue Mar 17 2015 - 04:50:37 EST


From: Felipe Balbi <balbi@xxxxxx>

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 RohÃr <pali.rohar@xxxxxxxxx>
Signed-off-by: Felipe Balbi <balbi@xxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
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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