[PATCH v2 1/3] USB: phy: replace spinlock with mutex in OTG FSM

[Anton Tikhomirov]

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.tikhomi...@samsung.com>
---
 drivers/usb/phy/phy-fsl-usb.c |    7 +++----
 drivers/usb/phy/phy-fsm-usb.c |    7 +++----
 drivers/usb/phy/phy-fsm-usb.h |    2 +-
 3 files changed, 7 insertions(+), 9 deletions(-)

diff --git a/drivers/usb/phy/phy-fsl-usb.c b/drivers/usb/phy/phy-fsl-usb.c
index 7f3c73b..62d5af2 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 329c2d2..2817b04 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 7441b46..12ece58 100644
--- a/drivers/usb/phy/phy-fsm-usb.h
+++ b/drivers/usb/phy/phy-fsm-usb.h
@@ -110,7 +110,7 @@ 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 {
-- 
1.7.9.5


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