greybus: operation: fix locking issues

Fix unconditional re-enabling of interrupts in various operation
functions that can all be called with local interrupts disabled from USB
completion handlers.

Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

diff --git a/drivers/staging/greybus/operation.c b/drivers/staging/greybus/operation.c
index 50498ec3fdfa2bcbff903315090a7e3fe5c2d3c8..5e859c04b716f9f5e731522218c683a9d034578d 100644 (file)
--- a/drivers/staging/greybus/operation.c
+++ b/drivers/staging/greybus/operation.c
@@ -94,6 +94,7 @@ static DEFINE_SPINLOCK(gb_operations_lock);
  */
 static bool gb_operation_result_set(struct gb_operation *operation, int result)
 {
+       unsigned long flags;
        int prev;
 
        if (result == -EINPROGRESS) {
@@ -104,13 +105,13 @@ static bool gb_operation_result_set(struct gb_operation *operation, int result)
                 * and record an implementation error if it's
                 * set at any other time.
                 */
-               spin_lock_irq(&gb_operations_lock);
+               spin_lock_irqsave(&gb_operations_lock, flags);
                prev = operation->errno;
                if (prev == -EBADR)
                        operation->errno = result;
                else
                        operation->errno = -EILSEQ;
-               spin_unlock_irq(&gb_operations_lock);
+               spin_unlock_irqrestore(&gb_operations_lock, flags);
                WARN_ON(prev != -EBADR);
 
                return true;
@@ -128,11 +129,11 @@ static bool gb_operation_result_set(struct gb_operation *operation, int result)
        if (WARN_ON(result == -EBADR))
                result = -EILSEQ; /* Nobody should be setting -EBADR */
 
-       spin_lock_irq(&gb_operations_lock);
+       spin_lock_irqsave(&gb_operations_lock, flags);
        prev = operation->errno;
        if (prev == -EINPROGRESS)
                operation->errno = result;      /* First and final result */
-       spin_unlock_irq(&gb_operations_lock);
+       spin_unlock_irqrestore(&gb_operations_lock, flags);
 
        return prev == -EINPROGRESS;
 }
@@ -151,15 +152,16 @@ static struct gb_operation *
 gb_operation_find(struct gb_connection *connection, u16 operation_id)
 {
        struct gb_operation *operation;
+       unsigned long flags;
        bool found = false;
 
-       spin_lock_irq(&gb_operations_lock);
+       spin_lock_irqsave(&gb_operations_lock, flags);
        list_for_each_entry(operation, &connection->operations, links)
                if (operation->id == operation_id) {
                        found = true;
                        break;
                }
-       spin_unlock_irq(&gb_operations_lock);
+       spin_unlock_irqrestore(&gb_operations_lock, flags);
 
        return found ? operation : NULL;
 }
@@ -490,6 +492,7 @@ gb_operation_create_common(struct gb_connection *connection, u8 type,
 {
        struct greybus_host_device *hd = connection->hd;
        struct gb_operation *operation;
+       unsigned long flags;
        gfp_t gfp_flags;
 
        /*
@@ -525,9 +528,9 @@ gb_operation_create_common(struct gb_connection *connection, u8 type,
        init_completion(&operation->completion);
        kref_init(&operation->kref);
 
-       spin_lock_irq(&gb_operations_lock);
+       spin_lock_irqsave(&gb_operations_lock, flags);
        list_add_tail(&operation->links, &connection->operations);
-       spin_unlock_irq(&gb_operations_lock);
+       spin_unlock_irqrestore(&gb_operations_lock, flags);
 
        return operation;
 
@@ -593,13 +596,14 @@ void gb_operation_get(struct gb_operation *operation)
 static void _gb_operation_destroy(struct kref *kref)
 {
        struct gb_operation *operation;
+       unsigned long flags;
 
        operation = container_of(kref, struct gb_operation, kref);
 
        /* XXX Make sure it's not in flight */
-       spin_lock_irq(&gb_operations_lock);
+       spin_lock_irqsave(&gb_operations_lock, flags);
        list_del(&operation->links);
-       spin_unlock_irq(&gb_operations_lock);
+       spin_unlock_irqrestore(&gb_operations_lock, flags);
 
        gb_operation_message_free(operation->response);
        gb_operation_message_free(operation->request);