USB: fixed bug in usbsevseg using USB autosuspend incorrectly

This patch fixes a bug with the usbsevseg driver which assumed that USB
autosuspend will always be used.

Signed-off-by: Harrison Metzger <harrisonmetz@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 13 insertions, 2 deletions

diff --git a/drivers/usb/misc/usbsevseg.c b/drivers/usb/misc/usbsevseg.c
index a9555cb901a..de8ef945b53 100644
--- a/drivers/usb/misc/usbsevseg.c
+++ b/drivers/usb/misc/usbsevseg.c
@@ -49,6 +49,7 @@ struct usb_sevsegdev {
         u16 textlength;
 
         u8 shadow_power; /* for PM */
+        u8 has_interface_pm;
 };
 
 /* sysfs_streq can't replace this completely
@@ -68,12 +69,16 @@ static void update_display_powered(struct usb_sevsegdev *mydev)
 {
         int rc;
 
-        if (!mydev->shadow_power && mydev->powered) {
+        if (mydev->powered && !mydev->has_interface_pm) {
                 rc = usb_autopm_get_interface(mydev->intf);
                 if (rc < 0)
                         return;
+                mydev->has_interface_pm = 1;
         }
 
+        if (mydev->shadow_power != 1)
+                return;
+
         rc = usb_control_msg(mydev->udev,
                         usb_sndctrlpipe(mydev->udev, 0),
                         0x12,
@@ -86,8 +91,10 @@ static void update_display_powered(struct usb_sevsegdev *mydev)
         if (rc < 0)
                 dev_dbg(&mydev->udev->dev, "power retval = %d\n", rc);
 
-        if (mydev->shadow_power && !mydev->powered)
+        if (!mydev->powered && mydev->has_interface_pm) {
                 usb_autopm_put_interface(mydev->intf);
+                mydev->has_interface_pm = 0;
+        }
 }
 
 static void update_display_mode(struct usb_sevsegdev *mydev)
@@ -351,6 +358,10 @@ static int sevseg_probe(struct usb_interface *interface,
         mydev->intf = interface;
         usb_set_intfdata(interface, mydev);
 
+        /* PM */
+        mydev->shadow_power = 1; /* currently active */
+        mydev->has_interface_pm = 0; /* have not issued autopm_get */
+
         /*set defaults */
         mydev->textmode = 0x02; /* ascii mode */
         mydev->mode_msb = 0x06; /* 6 characters */