usb: phy: replace spinlock with mutex in OTG FSM

OTG Final State Machine calls functions which may sleep.

For example, start_gadget callback implementation can use
usb_gadget_vbus_connect(), whose context: can sleep.

If so, mutex should be used instead of spinlock.

Signed-off-by: Anton Tikhomirov <av.tikhomirov@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
(cherry-picked from commit 16e569e9661ea2b964b8abb607a51e5285254021)

3 files changed, 8 insertions, 10 deletions

diff --git a/drivers/usb/phy/phy-fsl-usb.c b/drivers/usb/phy/phy-fsl-usb.c
index d58a510d0287..880172830473 100644
--- a/drivers/usb/phy/phy-fsl-usb.c
+++ b/drivers/usb/phy/phy-fsl-usb.c
@@ -848,7 +848,7 @@ static int fsl_otg_conf(struct platform_device *pdev)
                 pr_info("Couldn't init OTG timers\n");
                 goto err;
         }
-        spin_lock_init(&fsl_otg_tc->fsm.lock);
+        mutex_init(&fsl_otg_tc->fsm.lock);
 
         /* Set OTG state machine operations */
         fsl_otg_tc->fsm.ops = &fsl_otg_ops;
@@ -1017,10 +1017,9 @@ static int show_fsl_usb2_otg_state(struct device *dev,
         struct otg_fsm *fsm = &fsl_otg_dev->fsm;
         char *next = buf;
         unsigned size = PAGE_SIZE;
-        unsigned long flags;
         int t;
 
-        spin_lock_irqsave(&fsm->lock, flags);
+        mutex_lock(&fsm->lock);
 
         /* basic driver infomation */
         t = scnprintf(next, size,
@@ -1088,7 +1087,7 @@ static int show_fsl_usb2_otg_state(struct device *dev,
         size -= t;
         next += t;
 
-        spin_unlock_irqrestore(&fsm->lock, flags);
+        mutex_unlock(&fsm->lock);
 
         return PAGE_SIZE - size;
 }
diff --git a/drivers/usb/phy/phy-fsm-usb.c b/drivers/usb/phy/phy-fsm-usb.c
index 329c2d2f8595..2817b04a6c47 100644
--- a/drivers/usb/phy/phy-fsm-usb.c
+++ b/drivers/usb/phy/phy-fsm-usb.c
@@ -23,7 +23,7 @@
 
 #include <linux/kernel.h>
 #include <linux/types.h>
-#include <linux/spinlock.h>
+#include <linux/mutex.h>
 #include <linux/delay.h>
 #include <linux/usb.h>
 #include <linux/usb/gadget.h>
@@ -245,9 +245,8 @@ int otg_set_state(struct otg_fsm *fsm, enum usb_otg_state new_state)
 int otg_statemachine(struct otg_fsm *fsm)
 {
         enum usb_otg_state state;
-        unsigned long flags;
 
-        spin_lock_irqsave(&fsm->lock, flags);
+        mutex_lock(&fsm->lock);
 
         state = fsm->otg->phy->state;
         state_changed = 0;
@@ -359,7 +358,7 @@ int otg_statemachine(struct otg_fsm *fsm)
         default:
                 break;
         }
-        spin_unlock_irqrestore(&fsm->lock, flags);
+        mutex_lock(&fsm->lock);
 
         VDBG("quit statemachine, changed = %d\n", state_changed);
         return state_changed;
diff --git a/drivers/usb/phy/phy-fsm-usb.h b/drivers/usb/phy/phy-fsm-usb.h
index 200f4d156020..b6ba1bfb86f2 100644
--- a/drivers/usb/phy/phy-fsm-usb.h
+++ b/drivers/usb/phy/phy-fsm-usb.h
@@ -18,7 +18,7 @@
 #ifndef __LINUX_USB_OTG_FSM_H
 #define __LINUX_USB_OTG_FSM_H
 
-#include <linux/spinlock.h>
+#include <linux/mutex.h>
 #include <linux/errno.h>
 
 #undef VERBOSE
@@ -116,7 +116,7 @@ struct otg_fsm {
 
         /* Current usb protocol used: 0:undefine; 1:host; 2:client */
         int protocol;
-        spinlock_t lock;
+        struct mutex lock;
 };
 
 struct otg_fsm_ops {