viafb: Fix various resource leaks during module_init()

The current code executed from module_init() in viafb does not have
proper error checking and [partial] resoure release paths in case
an error happens half way through driver initialization.

This patch adresses the most obvious of those issues, such as a
leftover i2c bus if module_init (and thus module load) fails.

[jc: fixed merge conflicts]
[jc: also restored -ENOMEM return on ioremap() fail]

Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Cc: ScottFang@viatech.com.cn
Cc: JosephChan@via.com.tw
Signed-off-by: Harald Welte <HaraldWelte@viatech.com>

drivers/video/via/viafbdev.c

@@ -1,5 +1,5 @@
 /*
- * Copyright 1998-2008 VIA Technologies, Inc. All Rights Reserved.
+ * Copyright 1998-2009 VIA Technologies, Inc. All Rights Reserved.
  * Copyright 2001-2008 S3 Graphics, Inc. All Rights Reserved.
 
  * This program is free software; you can redistribute it and/or
@@ -1737,6 +1737,7 @@ static int __devinit via_pci_probe(struct pci_dev *pdev,
 	u32 default_xres, default_yres;
 	struct VideoModeTable *vmode_entry;
 	struct fb_var_screeninfo default_var;
+	int rc;
 	u32 viafb_par_length;
 
 	DEBUG_MSG(KERN_INFO "VIAFB PCI Probe!!\n");
@@ -1751,7 +1752,7 @@ static int __devinit via_pci_probe(struct pci_dev *pdev,
 		&pdev->dev);
 	if (!viafbinfo) {
 		printk(KERN_ERR"Could not allocate memory for viafb_info.\n");
-		return -ENODEV;
+		return -ENOMEM;
 	}
 
 	viaparinfo = (struct viafb_par *)viafbinfo->par;
@@ -1774,7 +1775,9 @@ static int __devinit via_pci_probe(struct pci_dev *pdev,
 		viafb_dual_fb = 0;
 
 	/* Set up I2C bus stuff */
-	viafb_create_i2c_bus(viaparinfo);
+	rc = viafb_create_i2c_bus(viaparinfo);
+	if (rc)
+		goto out_fb_release;
 
 	viafb_init_chip_info(pdev, ent);
 	viaparinfo->fbmem = pci_resource_start(pdev, 0);
@@ -1785,7 +1788,8 @@ static int __devinit via_pci_probe(struct pci_dev *pdev,
 		viaparinfo->memsize);
 	if (!viafbinfo->screen_base) {
 		printk(KERN_INFO "ioremap failed\n");
-		return -ENOMEM;
+		rc = -ENOMEM;
+		goto out_delete_i2c;
 	}
 
 	viafbinfo->fix.mmio_start = pci_resource_start(pdev, 1);
@@ -1861,8 +1865,8 @@ static int __devinit via_pci_probe(struct pci_dev *pdev,
 		if (!viafbinfo1) {
 			printk(KERN_ERR
 			"allocate the second framebuffer struct error\n");
-			framebuffer_release(viafbinfo);
-			return -ENOMEM;
+			rc = -ENOMEM;
+			goto out_delete_i2c;
 		}
 		viaparinfo1 = viafbinfo1->par;
 		memcpy(viaparinfo1, viaparinfo, viafb_par_length);
@@ -1913,21 +1917,26 @@ static int __devinit via_pci_probe(struct pci_dev *pdev,
 	viaparinfo->depth = fb_get_color_depth(&viafbinfo->var,
 		&viafbinfo->fix);
 	default_var.activate = FB_ACTIVATE_NOW;
-	fb_alloc_cmap(&viafbinfo->cmap, 256, 0);
+	rc = fb_alloc_cmap(&viafbinfo->cmap, 256, 0);
+	if (rc)
+		goto out_fb1_release;
 
 	if (viafb_dual_fb && (viafb_primary_dev == LCD_Device)
 	    && (viaparinfo->chip_info->gfx_chip_name == UNICHROME_CLE266)) {
-		if (register_framebuffer(viafbinfo1) < 0)
-			return -EINVAL;
+		rc = register_framebuffer(viafbinfo1);
+		if (rc)
+			goto out_dealloc_cmap;
 	}
-	if (register_framebuffer(viafbinfo) < 0)
-		return -EINVAL;
+	rc = register_framebuffer(viafbinfo);
+	if (rc)
+		goto out_fb1_unreg_lcd_cle266;
 
 	if (viafb_dual_fb && ((viafb_primary_dev != LCD_Device)
 			|| (viaparinfo->chip_info->gfx_chip_name !=
 			UNICHROME_CLE266))) {
-		if (register_framebuffer(viafbinfo1) < 0)
-			return -EINVAL;
+		rc = register_framebuffer(viafbinfo1);
+		if (rc)
+			goto out_fb_unreg;
 	}
 	DEBUG_MSG(KERN_INFO "fb%d: %s frame buffer device %dx%d-%dbpp\n",
 		  viafbinfo->node, viafbinfo->fix.id, default_var.xres,
@@ -1936,6 +1945,23 @@ static int __devinit via_pci_probe(struct pci_dev *pdev,
 	viafb_init_proc(&viaparinfo->shared->proc_entry);
 	viafb_init_dac(IGA2);
 	return 0;
+
+out_fb_unreg:
+	unregister_framebuffer(viafbinfo);
+out_fb1_unreg_lcd_cle266:
+	if (viafb_dual_fb && (viafb_primary_dev == LCD_Device)
+	    && (viaparinfo->chip_info->gfx_chip_name == UNICHROME_CLE266))
+		unregister_framebuffer(viafbinfo1);
+out_dealloc_cmap:
+	fb_dealloc_cmap(&viafbinfo->cmap);
+out_fb1_release:
+	if (viafbinfo1)
+		framebuffer_release(viafbinfo1);
+out_delete_i2c:
+	viafb_delete_i2c_buss(viaparinfo);
+out_fb_release:
+	framebuffer_release(viafbinfo);
+	return rc;
 }
 
 static void __devexit via_pci_remove(struct pci_dev *pdev)