grvga: Fix error handling issues

This patch fixes two problems with the error handling in the
grvga_probe function and simplifies it making the code
easier to read.

- If the call to grvga_parse_custom on line 370 fails we use
  the wrong label so that release_mem_region will be called
  without a call to request_mem_region being made.

- If the call to ioremap on line 436 fails we should not try
  to call iounmap in the error handling code.

This patch introduces the following changes:

- Converts request_mem_region into its devm_ equivalent
  which simplifies the otherwise messy clean up code.

- Changes the labels for correct error handling and their
  names to make the code easier to read.
Signed-off-by: Emil Goode <emilgoode@gmail.com>
Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>

drivers/video/grvga.c

@@ -354,7 +354,7 @@ static int __devinit grvga_probe(struct platform_device *dev)
 	 */
 	if (fb_get_options("grvga", &options)) {
 		retval = -ENODEV;
-		goto err;
+		goto free_fb;
 	}
 
 	if (!options || !*options)
@@ -370,7 +370,7 @@ static int __devinit grvga_probe(struct platform_device *dev)
 			if (grvga_parse_custom(this_opt, &info->var) < 0) {
 				dev_err(&dev->dev, "Failed to parse custom mode (%s).\n", this_opt);
 				retval = -EINVAL;
-				goto err1;
+				goto free_fb;
 			}
 		} else if (!strncmp(this_opt, "addr", 4))
 			grvga_fix_addr = simple_strtoul(this_opt + 5, NULL, 16);
@@ -387,10 +387,11 @@ static int __devinit grvga_probe(struct platform_device *dev)
 	info->flags = FBINFO_DEFAULT | FBINFO_PARTIAL_PAN_OK | FBINFO_HWACCEL_YPAN;
 	info->fix.smem_len = grvga_mem_size;
 
-	if (!request_mem_region(dev->resource[0].start, resource_size(&dev->resource[0]), "grlib-svgactrl regs")) {
+	if (!devm_request_mem_region(&dev->dev, dev->resource[0].start,
+		    resource_size(&dev->resource[0]), "grlib-svgactrl regs")) {
 		dev_err(&dev->dev, "registers already mapped\n");
 		retval = -EBUSY;
-		goto err;
+		goto free_fb;
 	}
 
 	par->regs = of_ioremap(&dev->resource[0], 0,
@@ -400,14 +401,14 @@ static int __devinit grvga_probe(struct platform_device *dev)
 	if (!par->regs) {
 		dev_err(&dev->dev, "failed to map registers\n");
 		retval = -ENOMEM;
-		goto err1;
+		goto free_fb;
 	}
 
 	retval = fb_alloc_cmap(&info->cmap, 256, 0);
 	if (retval < 0) {
 		dev_err(&dev->dev, "failed to allocate mem with fb_alloc_cmap\n");
 		retval = -ENOMEM;
-		goto err2;
+		goto unmap_regs;
 	}
 
 	if (mode_opt) {
@@ -415,7 +416,7 @@ static int __devinit grvga_probe(struct platform_device *dev)
 				      grvga_modedb, sizeof(grvga_modedb), &grvga_modedb[0], 8);
 		if (!retval || retval == 4) {
 			retval = -EINVAL;
-			goto err3;
+			goto dealloc_cmap;
 		}
 	}
 
@@ -427,10 +428,11 @@ static int __devinit grvga_probe(struct platform_device *dev)
 
 		physical_start = grvga_fix_addr;
 
-		if (!request_mem_region(physical_start, grvga_mem_size, dev->name)) {
+		if (!devm_request_mem_region(&dev->dev, physical_start,
+					     grvga_mem_size, dev->name)) {
 			dev_err(&dev->dev, "failed to request memory region\n");
 			retval = -ENOMEM;
-			goto err3;
+			goto dealloc_cmap;
 		}
 
 		virtual_start = (unsigned long) ioremap(physical_start, grvga_mem_size);
@@ -438,7 +440,7 @@ static int __devinit grvga_probe(struct platform_device *dev)
 		if (!virtual_start) {
 			dev_err(&dev->dev, "error mapping framebuffer memory\n");
 			retval = -ENOMEM;
-			goto err4;
+			goto dealloc_cmap;
 		}
 	} else {	/* Allocate frambuffer memory */
 
@@ -451,7 +453,7 @@ static int __devinit grvga_probe(struct platform_device *dev)
 				"unable to allocate framebuffer memory (%lu bytes)\n",
 				grvga_mem_size);
 			retval = -ENOMEM;
-			goto err3;
+			goto dealloc_cmap;
 		}
 
 		physical_start = dma_map_single(&dev->dev, (void *)virtual_start, grvga_mem_size, DMA_TO_DEVICE);
@@ -484,7 +486,7 @@ static int __devinit grvga_probe(struct platform_device *dev)
 	retval = register_framebuffer(info);
 	if (retval < 0) {
 		dev_err(&dev->dev, "failed to register framebuffer\n");
-		goto err4;
+		goto free_mem;
 	}
 
 	__raw_writel(physical_start, &par->regs->fb_pos);
@@ -493,21 +495,18 @@ static int __devinit grvga_probe(struct platform_device *dev)
 
 	return 0;
 
-err4:
+free_mem:
 	dev_set_drvdata(&dev->dev, NULL);
-	if (grvga_fix_addr) {
-		release_mem_region(physical_start, grvga_mem_size);
+	if (grvga_fix_addr)
 		iounmap((void *)virtual_start);
-	} else
+	else
 		kfree((void *)virtual_start);
-err3:
+dealloc_cmap:
 	fb_dealloc_cmap(&info->cmap);
-err2:
+unmap_regs:
 	of_iounmap(&dev->resource[0], par->regs,
 		   resource_size(&dev->resource[0]));
-err1:
-	release_mem_region(dev->resource[0].start, resource_size(&dev->resource[0]));
-err:
+free_fb:
 	framebuffer_release(info);
 
 	return retval;
@@ -524,12 +523,10 @@ static int __devexit grvga_remove(struct platform_device *device)
 
 		of_iounmap(&device->resource[0], par->regs,
 			   resource_size(&device->resource[0]));
-		release_mem_region(device->resource[0].start, resource_size(&device->resource[0]));
 
-		if (!par->fb_alloced) {
-			release_mem_region(info->fix.smem_start, info->fix.smem_len);
+		if (!par->fb_alloced)
 			iounmap(info->screen_base);
-		} else
+		else
 			kfree((void *)info->screen_base);
 
 		framebuffer_release(info);