diff --git a/drivers/acpi/proc.c b/drivers/acpi/proc.c
index f8b6f555ba52..d0d25e2e1ced 100644
--- a/drivers/acpi/proc.c
+++ b/drivers/acpi/proc.c
@@ -393,7 +393,7 @@ acpi_system_write_wakeup_device(struct file *file,
 	struct list_head *node, *next;
 	char strbuf[5];
 	char str[5] = "";
-	int len = count;
+	unsigned int len = count;
 	struct acpi_device *found_dev = NULL;
 
 	if (len > 4)
diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
index 64e3c581b7a9..05dff631591c 100644
--- a/drivers/acpi/video.c
+++ b/drivers/acpi/video.c
@@ -1223,7 +1223,7 @@ acpi_video_device_write_state(struct file *file,
 	u32 state = 0;
 
 
-	if (!dev || count + 1 > sizeof str)
+	if (!dev || count >= sizeof(str))
 		return -EINVAL;
 
 	if (copy_from_user(str, buffer, count))
@@ -1280,7 +1280,7 @@ acpi_video_device_write_brightness(struct file *file,
 	int i;
 
 
-	if (!dev || !dev->brightness || count + 1 > sizeof str)
+	if (!dev || !dev->brightness || count >= sizeof(str))
 		return -EINVAL;
 
 	if (copy_from_user(str, buffer, count))
@@ -1562,7 +1562,7 @@ acpi_video_bus_write_POST(struct file *file,
 	unsigned long long opt, options;
 
 
-	if (!video || count + 1 > sizeof str)
+	if (!video || count >= sizeof(str))
 		return -EINVAL;
 
 	status = acpi_video_bus_POST_options(video, &options);
@@ -1602,7 +1602,7 @@ acpi_video_bus_write_DOS(struct file *file,
 	unsigned long opt;
 
 
-	if (!video || count + 1 > sizeof str)
+	if (!video || count >= sizeof(str))
 		return -EINVAL;
 
 	if (copy_from_user(str, buffer, count))