[PATCH] USB: convert a bunch of USB semaphores to mutexes

the patch below converts a bunch of semaphores-used-as-mutex in the USB
code to mutexes

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

3 files changed, 21 insertions, 18 deletions

diff --git a/drivers/usb/storage/scsiglue.c b/drivers/usb/storage/scsiglue.c
index 4ef5527028c5..5f11e19eaae3 100644
--- a/drivers/usb/storage/scsiglue.c
+++ b/drivers/usb/storage/scsiglue.c
@@ -47,6 +47,7 @@
 
 #include <linux/slab.h>
 #include <linux/module.h>
+#include <linux/mutex.h>
 
 #include <scsi/scsi.h>
 #include <scsi/scsi_cmnd.h>
@@ -271,9 +272,9 @@ static int device_reset(struct scsi_cmnd *srb)
         US_DEBUGP("%s called\n", __FUNCTION__);
 
         /* lock the device pointers and do the reset */
-        down(&(us->dev_semaphore));
+        mutex_lock(&(us->dev_mutex));
         result = us->transport_reset(us);
-        up(&(us->dev_semaphore));
+        mutex_unlock(&us->dev_mutex);
 
         return result < 0 ? FAILED : SUCCESS;
 }
@@ -286,9 +287,9 @@ static int bus_reset(struct scsi_cmnd *srb)
 
         US_DEBUGP("%s called\n", __FUNCTION__);
 
-        down(&(us->dev_semaphore));
+        mutex_lock(&(us->dev_mutex));
         result = usb_stor_port_reset(us);
-        up(&(us->dev_semaphore));
+        mutex_unlock(&us->dev_mutex);
 
         return result < 0 ? FAILED : SUCCESS;
 }
diff --git a/drivers/usb/storage/usb.c b/drivers/usb/storage/usb.c
index dbcf23980ff1..dd108634348e 100644
--- a/drivers/usb/storage/usb.c
+++ b/drivers/usb/storage/usb.c
@@ -55,6 +55,7 @@
 #include <linux/init.h>
 #include <linux/slab.h>
 #include <linux/kthread.h>
+#include <linux/mutex.h>
 
 #include <scsi/scsi.h>
 #include <scsi/scsi_cmnd.h>
@@ -188,7 +189,7 @@ static int storage_suspend(struct usb_interface *iface, pm_message_t message)
         struct us_data *us = usb_get_intfdata(iface);
 
         /* Wait until no command is running */
-        down(&us->dev_semaphore);
+        mutex_lock(&us->dev_mutex);
 
         US_DEBUGP("%s\n", __FUNCTION__);
         if (us->suspend_resume_hook)
@@ -198,7 +199,7 @@ static int storage_suspend(struct usb_interface *iface, pm_message_t message)
         /* When runtime PM is working, we'll set a flag to indicate
          * whether we should autoresume when a SCSI request arrives. */
 
-        up(&us->dev_semaphore);
+        mutex_unlock(&us->dev_mutex);
         return 0;
 }
 
@@ -206,14 +207,14 @@ static int storage_resume(struct usb_interface *iface)
 {
         struct us_data *us = usb_get_intfdata(iface);
 
-        down(&us->dev_semaphore);
+        mutex_lock(&us->dev_mutex);
 
         US_DEBUGP("%s\n", __FUNCTION__);
         if (us->suspend_resume_hook)
                 (us->suspend_resume_hook)(us, US_RESUME);
         iface->dev.power.power_state.event = PM_EVENT_ON;
 
-        up(&us->dev_semaphore);
+        mutex_unlock(&us->dev_mutex);
         return 0;
 }
 
@@ -276,12 +277,12 @@ static int usb_stor_control_thread(void * __us)
                 US_DEBUGP("*** thread awakened.\n");
 
                 /* lock the device pointers */
-                down(&(us->dev_semaphore));
+                mutex_lock(&(us->dev_mutex));
 
                 /* if the device has disconnected, we are free to exit */
                 if (test_bit(US_FLIDX_DISCONNECTING, &us->flags)) {
                         US_DEBUGP("-- exiting\n");
-                        up(&(us->dev_semaphore));
+                        mutex_unlock(&us->dev_mutex);
                         break;
                 }
 
@@ -370,7 +371,7 @@ SkipForAbort:
                 scsi_unlock(host);
 
                 /* unlock the device pointers */
-                up(&(us->dev_semaphore));
+                mutex_unlock(&us->dev_mutex);
         } /* for (;;) */
 
         scsi_host_put(host);
@@ -815,8 +816,8 @@ static void quiesce_and_remove_host(struct us_data *us)
          * The thread will exit when it sees the DISCONNECTING flag. */
 
         /* Wait for the current command to finish, then remove the host */
-        down(&us->dev_semaphore);
-        up(&us->dev_semaphore);
+        mutex_lock(&us->dev_mutex);
+        mutex_unlock(&us->dev_mutex);
 
         /* queuecommand won't accept any new commands and the control
          * thread won't execute a previously-queued command.  If there
@@ -870,9 +871,9 @@ retry:
                 /* For bulk-only devices, determine the max LUN value */
                 if (us->protocol == US_PR_BULK &&
                                 !(us->flags & US_FL_SINGLE_LUN)) {
-                        down(&us->dev_semaphore);
+                        mutex_lock(&us->dev_mutex);
                         us->max_lun = usb_stor_Bulk_max_lun(us);
-                        up(&us->dev_semaphore);
+                        mutex_unlock(&us->dev_mutex);
                 }
                 scsi_scan_host(us_to_host(us));
                 printk(KERN_DEBUG "usb-storage: device scan complete\n");
@@ -912,7 +913,7 @@ static int storage_probe(struct usb_interface *intf,
 
         us = host_to_us(host);
         memset(us, 0, sizeof(struct us_data));
-        init_MUTEX(&(us->dev_semaphore));
+        mutex_init(&(us->dev_mutex));
         init_MUTEX_LOCKED(&(us->sema));
         init_completion(&(us->notify));
         init_waitqueue_head(&us->delay_wait);
diff --git a/drivers/usb/storage/usb.h b/drivers/usb/storage/usb.h
index 7259fd1f6b0d..009fb0953a56 100644
--- a/drivers/usb/storage/usb.h
+++ b/drivers/usb/storage/usb.h
@@ -49,6 +49,7 @@
 #include <linux/blkdev.h>
 #include <linux/smp_lock.h>
 #include <linux/completion.h>
+#include <linux/mutex.h>
 #include <scsi/scsi_host.h>
 
 struct us_data;
@@ -103,9 +104,9 @@ typedef void (*pm_hook)(struct us_data *, int);	/* power management hook */
 struct us_data {
         /* The device we're working with
          * It's important to note:
-         *    (o) you must hold dev_semaphore to change pusb_dev
+         *    (o) you must hold dev_mutex to change pusb_dev
          */
-        struct semaphore        dev_semaphore;   /* protect pusb_dev */
+        struct mutex            dev_mutex;       /* protect pusb_dev */
         struct usb_device       *pusb_dev;       /* this usb_device */
         struct usb_interface    *pusb_intf;      /* this interface */
         struct us_unusual_dev   *unusual_dev;    /* device-filter entry     */