sony-laptop: add locking on accesses to the ioport and global vars

Better avoid having ioport commands mixing and global variables reading/writing.

Signed-off-by: Mattia Dongili <malattia@linux.it>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 31 insertions, 12 deletions

diff --git a/drivers/misc/sony-laptop.c b/drivers/misc/sony-laptop.c
index 09e75390ac98..56413435c531 100644
--- a/drivers/misc/sony-laptop.c
+++ b/drivers/misc/sony-laptop.c
@@ -928,6 +928,7 @@ struct sony_pic_dev {
         struct sony_pic_ioport  *cur_ioport;
         struct list_head        interrupts;
         struct list_head        ioports;
+        struct mutex            lock;
 };
 
 static struct sony_pic_dev spic_dev = {
@@ -1224,7 +1225,7 @@ static u8 sony_pic_call3(u8 dev, u8 fn, u8 v)
 #define SONYPI_CAMERA_STATUS_READY      0x2
 #define SONYPI_CAMERA_STATUS_POSITION   0x4
 
-static int sony_pic_camera_ready(void)
+static int __sony_pic_camera_ready(void)
 {
         u8 v;
 
@@ -1239,6 +1240,7 @@ static int sony_pic_camera_off(void)
                 return -ENODEV;
         }
 
+        mutex_lock(&spic_dev.lock);
         wait_on_command(sony_pic_call3(0x90, SONYPI_CAMERA_PICTURE,
                                 SONYPI_CAMERA_MUTE_MASK),
                         ITERATIONS_SHORT);
@@ -1247,20 +1249,23 @@ static int sony_pic_camera_off(void)
                 sony_pic_call2(0x91, 0);
                 spic_dev.camera_power = 0;
         }
+        mutex_unlock(&spic_dev.lock);
         return 0;
 }
 
 static int sony_pic_camera_on(void)
 {
         int i, j, x;
+        int result = 0;
 
         if (!camera) {
                 printk(KERN_WARNING DRV_PFX "camera control not enabled\n");
                 return -ENODEV;
         }
 
+        mutex_lock(&spic_dev.lock);
         if (spic_dev.camera_power)
-                return 0;
+                goto out_unlock;
 
         for (j = 5; j > 0; j--) {
 
@@ -1269,7 +1274,7 @@ static int sony_pic_camera_on(void)
                 sony_pic_call1(0x93);
 
                 for (i = 400; i > 0; i--) {
-                        if (sony_pic_camera_ready())
+                        if (__sony_pic_camera_ready())
                                 break;
                         msleep(10);
                 }
@@ -1279,7 +1284,8 @@ static int sony_pic_camera_on(void)
 
         if (j == 0) {
                 printk(KERN_WARNING DRV_PFX "failed to power on camera\n");
-                return -ENODEV;
+                result = -ENODEV;
+                goto out_unlock;
         }
 
         wait_on_command(sony_pic_call3(0x90, SONYPI_CAMERA_CONTROL,
@@ -1287,6 +1293,9 @@ static int sony_pic_camera_on(void)
                         ITERATIONS_SHORT);
 
         spic_dev.camera_power = 1;
+
+out_unlock:
+        mutex_unlock(&spic_dev.lock);
         return 0;
 }
 
@@ -1314,11 +1323,15 @@ static ssize_t sony_pic_camerapower_store(struct device *dev,
 static ssize_t sony_pic_camerapower_show(struct device *dev,
                 struct device_attribute *attr, char *buffer)
 {
-        return snprintf(buffer, PAGE_SIZE, "%d\n", spic_dev.camera_power);
+        ssize_t count;
+        mutex_lock(&spic_dev.lock);
+        count = snprintf(buffer, PAGE_SIZE, "%d\n", spic_dev.camera_power);
+        mutex_unlock(&spic_dev.lock);
+        return count;
 }
 
 /* bluetooth subsystem power state */
-static void sony_pic_set_bluetoothpower(u8 state)
+static void __sony_pic_set_bluetoothpower(u8 state)
 {
         state = !!state;
         if (spic_dev.bluetooth_power == state)
@@ -1337,7 +1350,9 @@ static ssize_t sony_pic_bluetoothpower_store(struct device *dev,
                 return -EINVAL;
 
         value = simple_strtoul(buffer, NULL, 10);
-        sony_pic_set_bluetoothpower(value);
+        mutex_lock(&spic_dev.lock);
+        __sony_pic_set_bluetoothpower(value);
+        mutex_unlock(&spic_dev.lock);
 
         return count;
 }
@@ -1345,7 +1360,11 @@ static ssize_t sony_pic_bluetoothpower_store(struct device *dev,
 static ssize_t sony_pic_bluetoothpower_show(struct device *dev,
                 struct device_attribute *attr, char *buffer)
 {
-        return snprintf(buffer, PAGE_SIZE, "%d\n", spic_dev.bluetooth_power);
+        ssize_t count = 0;
+        mutex_lock(&spic_dev.lock);
+        count = snprintf(buffer, PAGE_SIZE, "%d\n", spic_dev.bluetooth_power);
+        mutex_unlock(&spic_dev.lock);
+        return count;
 }
 
 /* fan speed */
@@ -1518,7 +1537,7 @@ static int sonypi_misc_ioctl(struct inode *ip, struct file *fp,
         u16 val16;
         int value;
 
-        /*down(&sonypi_device.lock);*/
+        mutex_lock(&spic_dev.lock);
         switch (cmd) {
         case SONYPI_IOCGBRT:
                 if (sony_backlight_device == NULL) {
@@ -1602,7 +1621,7 @@ static int sonypi_misc_ioctl(struct inode *ip, struct file *fp,
                         ret = -EFAULT;
                         break;
                 }
-                sony_pic_set_bluetoothpower(val8);
+                __sony_pic_set_bluetoothpower(val8);
                 break;
         /* FAN Controls */
         case SONYPI_IOCGFAN:
@@ -1633,7 +1652,7 @@ static int sonypi_misc_ioctl(struct inode *ip, struct file *fp,
         default:
                 ret = -EINVAL;
         }
-        /*up(&sonypi_device.lock);*/
+        mutex_unlock(&spic_dev.lock);
         return ret;
 }
 
@@ -1673,7 +1692,6 @@ static int sonypi_compat_init(void)
         }
 
         init_waitqueue_head(&sonypi_compat.fifo_proc_list);
-        /*init_MUTEX(&sonypi_device.lock);*/
 
         if (minor != -1)
                 sonypi_misc_device.minor = minor;
@@ -2004,6 +2022,7 @@ static int sony_pic_add(struct acpi_device *device)
         spic_dev.acpi_dev = device;
         strcpy(acpi_device_class(device), "sony/hotkey");
         spic_dev.model = sony_pic_detect_device_type();
+        mutex_init(&spic_dev.lock);
 
         /* read _PRS resources */
         result = sony_pic_possible_resources(device);