Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab...

[pandora-kernel.git] / drivers / media / rc / imon.c

diff --git a/drivers/media/rc/imon.c b/drivers/media/rc/imon.c
index ebd68ed..8fc0f08 100644 (file)
--- a/drivers/media/rc/imon.c
+++ b/drivers/media/rc/imon.c
@@ -46,7 +46,7 @@
 #define MOD_AUTHOR     "Jarod Wilson <jarod@wilsonet.com>"
 #define MOD_DESC       "Driver for SoundGraph iMON MultiMedia IR/Display"
 #define MOD_NAME       "imon"
-#define MOD_VERSION    "0.9.2"
+#define MOD_VERSION    "0.9.3"
 
 #define DISPLAY_MINOR_BASE     144
 #define DEVICE_NAME    "lcd%d"
@@ -460,8 +460,9 @@ static int display_close(struct inode *inode, struct file *file)
 }
 
 /**
- * Sends a packet to the device -- this function must be called
- * with ictx->lock held.
+ * Sends a packet to the device -- this function must be called with
+ * ictx->lock held, or its unlock/lock sequence while waiting for tx
+ * to complete can/will lead to a deadlock.
  */
 static int send_packet(struct imon_context *ictx)
 {
@@ -991,12 +992,21 @@ static void imon_touch_display_timeout(unsigned long data)
  * the iMON remotes, and those used by the Windows MCE remotes (which is
  * really just RC-6), but only one or the other at a time, as the signals
  * are decoded onboard the receiver.
+ *
+ * This function gets called two different ways, one way is from
+ * rc_register_device, for initial protocol selection/setup, and the other is
+ * via a userspace-initiated protocol change request, either by direct sysfs
+ * prodding or by something like ir-keytable. In the rc_register_device case,
+ * the imon context lock is already held, but when initiated from userspace,
+ * it is not, so we must acquire it prior to calling send_packet, which
+ * requires that the lock is held.
  */
 static int imon_ir_change_protocol(struct rc_dev *rc, u64 rc_type)
 {
        int retval;
        struct imon_context *ictx = rc->priv;
        struct device *dev = ictx->dev;
+       bool unlock = false;
        unsigned char ir_proto_packet[] = {
                0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x86 };
 
@@ -1029,6 +1039,11 @@ static int imon_ir_change_protocol(struct rc_dev *rc, u64 rc_type)
 
        memcpy(ictx->usb_tx_buf, &ir_proto_packet, sizeof(ir_proto_packet));
 
+       if (!mutex_is_locked(&ictx->lock)) {
+               unlock = true;
+               mutex_lock(&ictx->lock);
+       }
+
        retval = send_packet(ictx);
        if (retval)
                goto out;
@@ -1037,6 +1052,9 @@ static int imon_ir_change_protocol(struct rc_dev *rc, u64 rc_type)
        ictx->pad_mouse = false;
 
 out:
+       if (unlock)
+               mutex_unlock(&ictx->lock);
+
        return retval;
 }
 
@@ -2134,6 +2152,7 @@ static struct imon_context *imon_init_intf0(struct usb_interface *intf)
                goto rdev_setup_failed;
        }
 
+       mutex_unlock(&ictx->lock);
        return ictx;
 
 rdev_setup_failed:
@@ -2205,6 +2224,7 @@ static struct imon_context *imon_init_intf1(struct usb_interface *intf,
                goto urb_submit_failed;
        }
 
+       mutex_unlock(&ictx->lock);
        return ictx;
 
 urb_submit_failed:
@@ -2299,6 +2319,8 @@ static int __devinit imon_probe(struct usb_interface *interface,
        usb_set_intfdata(interface, ictx);
 
        if (ifnum == 0) {
+               mutex_lock(&ictx->lock);
+
                if (product == 0xffdc && ictx->rf_device) {
                        sysfs_err = sysfs_create_group(&interface->dev.kobj,
                                                       &imon_rf_attr_group);
@@ -2309,13 +2331,14 @@ static int __devinit imon_probe(struct usb_interface *interface,
 
                if (ictx->display_supported)
                        imon_init_display(ictx, interface);
+
+               mutex_unlock(&ictx->lock);
        }
 
        dev_info(dev, "iMON device (%04x:%04x, intf%d) on "
                 "usb<%d:%d> initialized\n", vendor, product, ifnum,
                 usbdev->bus->busnum, usbdev->devnum);
 
-       mutex_unlock(&ictx->lock);
        mutex_unlock(&driver_lock);
 
        return 0;