[PATCH 4/6] EM28xx - clean up resources should init fail

[Chris Rankin <rankincj@xxxxxxxxx>]

This patch ensures that the em28xx_init_dev() function cleans up after itself, 
in the event that it fails. This isimportant because the struct em28xx will be 
deallocated if em28xx_init_dev() returns an error.

Signed-off-by: Chris Rankin <rankincj@xxxxxxxxx>

--- linux-3.0/drivers/media/video/em28xx/em28xx-cards.c.orig	2011-08-18 22:42:03.000000000 +0100
+++ linux-3.0/drivers/media/video/em28xx/em28xx-cards.c	2011-08-18 22:55:52.000000000 +0100
@@ -2776,7 +2776,6 @@
 {
 	struct em28xx *dev = *devhandle;
 	int retval;
-	int errCode;
 
 	dev->udev = udev;
 	mutex_init(&dev->ctrl_urb_lock);
@@ -2858,7 +2857,7 @@
 		/* Resets I2C speed */
 		em28xx_write_reg(dev, EM28XX_R06_I2C_CLK, dev->board.i2c_speed);
 		if (retval < 0) {
-			em28xx_errdev("%s: em28xx_write_regs_req failed!"
+			em28xx_errdev("%s: em28xx_write_reg failed!"
 				      " retval [%d]\n",
 				      __func__, retval);
 			return retval;
@@ -2872,12 +2871,11 @@
 	}
 
 	/* register i2c bus */
-	errCode = em28xx_i2c_register(dev);
-	if (errCode < 0) {
-		v4l2_device_unregister(&dev->v4l2_dev);
+	retval = em28xx_i2c_register(dev);
+	if (retval < 0) {
 		em28xx_errdev("%s: em28xx_i2c_register - errCode [%d]!\n",
-			__func__, errCode);
-		return errCode;
+			__func__, retval);
+		goto fail_reg_i2c;
 	}
 
 	/*
@@ -2891,11 +2889,11 @@
 	em28xx_card_setup(dev);
 
 	/* Configure audio */
-	errCode = em28xx_audio_setup(dev);
-	if (errCode < 0) {
-		v4l2_device_unregister(&dev->v4l2_dev);
+	retval = em28xx_audio_setup(dev);
+	if (retval < 0) {
 		em28xx_errdev("%s: Error while setting audio - errCode [%d]!\n",
-			__func__, errCode);
+			__func__, retval);
+		goto fail_setup_audio;
 	}
 
 	/* wake i2c devices */
@@ -2909,31 +2907,28 @@
 
 	if (dev->board.has_msp34xx) {
 		/* Send a reset to other chips via gpio */
-		errCode = em28xx_write_reg(dev, EM28XX_R08_GPIO, 0xf7);
-		if (errCode < 0) {
-			em28xx_errdev("%s: em28xx_write_regs_req - "
+		retval = em28xx_write_reg(dev, EM28XX_R08_GPIO, 0xf7);
+		if (retval < 0) {
+			em28xx_errdev("%s: em28xx_write_reg - "
 				      "msp34xx(1) failed! errCode [%d]\n",
-				      __func__, errCode);
-			return errCode;
+				      __func__, retval);
+			goto fail_write_reg;
 		}
 		msleep(3);
 
-		errCode = em28xx_write_reg(dev, EM28XX_R08_GPIO, 0xff);
-		if (errCode < 0) {
-			em28xx_errdev("%s: em28xx_write_regs_req - "
+		retval = em28xx_write_reg(dev, EM28XX_R08_GPIO, 0xff);
+		if (retval < 0) {
+			em28xx_errdev("%s: em28xx_write_reg - "
 				      "msp34xx(2) failed! errCode [%d]\n",
-				      __func__, errCode);
-			return errCode;
+				      __func__, retval);
+			goto fail_write_reg;
 		}
 		msleep(3);
 	}
 
-	em28xx_add_into_devlist(dev);
-
 	retval = em28xx_register_analog_devices(dev);
 	if (retval < 0) {
-		em28xx_release_resources(dev);
-		goto fail_reg_devices;
+		goto fail_reg_analog_devices;
 	}
 
 	em28xx_init_extension(dev);
@@ -2943,7 +2938,14 @@
 
 	return 0;
 
-fail_reg_devices:
+fail_setup_audio:
+fail_write_reg:
+fail_reg_analog_devices:
+	em28xx_i2c_unregister(dev);
+
+fail_reg_i2c:
+	v4l2_device_unregister(&dev->v4l2_dev);
+
 	return retval;
 }
 
--- linux-3.0/drivers/media/video/em28xx/em28xx-core.c.orig	2011-08-17 08:52:25.000000000 +0100
+++ linux-3.0/drivers/media/video/em28xx/em28xx-core.c	2011-08-18 22:51:59.000000000 +0100
@@ -1171,13 +1171,6 @@
 	mutex_unlock(&em28xx_devlist_mutex);
 };
 
-void em28xx_add_into_devlist(struct em28xx *dev)
-{
-	mutex_lock(&em28xx_devlist_mutex);
-	list_add_tail(&dev->devlist, &em28xx_devlist);
-	mutex_unlock(&em28xx_devlist_mutex);
-};
-
 /*
  * Extension interface
  */
@@ -1215,14 +1208,13 @@
 
 void em28xx_init_extension(struct em28xx *dev)
 {
-	struct em28xx_ops *ops = NULL;
+	const struct em28xx_ops *ops = NULL;
 
 	mutex_lock(&em28xx_devlist_mutex);
-	if (!list_empty(&em28xx_extension_devlist)) {
-		list_for_each_entry(ops, &em28xx_extension_devlist, next) {
-			if (ops->init)
-				ops->init(dev);
-		}
+	list_add_tail(&dev->devlist, &em28xx_devlist);
+	list_for_each_entry(ops, &em28xx_extension_devlist, next) {
+		if (ops->init)
+			ops->init(dev);
 	}
 	mutex_unlock(&em28xx_devlist_mutex);
 }