[PATCH] drivers/video/pmag-ba-fb.c: Improve diagnostics

["Maciej W. Rozycki" <macro@xxxxxxxxxxxxxx>]

 Add error messages to the probe call.

Signed-off-by: Maciej W. Rozycki <macro@xxxxxxxxxxxxxx>
---
 While they may rarely trigger, they may be useful when something weird is 
going on.  Also this is good style.

 Checked with checkpatch.pl and at the runtime.

 Please apply; don't be worried about the old version number.

  Maciej

patch-mips-2.6.18-20060920-pmag-ba-err-1
diff -up --recursive --new-file linux-mips-2.6.18-20060920.macro/drivers/video/pmag-ba-fb.c linux-mips-2.6.18-20060920/drivers/video/pmag-ba-fb.c
--- linux-mips-2.6.18-20060920.macro/drivers/video/pmag-ba-fb.c	2006-12-16 16:45:08.000000000 +0000
+++ linux-mips-2.6.18-20060920/drivers/video/pmag-ba-fb.c	2006-12-16 16:45:23.000000000 +0000
@@ -147,16 +147,23 @@ static int __init pmagbafb_probe(struct 
 	resource_size_t start, len;
 	struct fb_info *info;
 	struct pmagbafb_par *par;
+	int err = 0;
 
 	info = framebuffer_alloc(sizeof(struct pmagbafb_par), dev);
-	if (!info)
+	if (!info) {
+		printk(KERN_ERR "%s: Cannot allocate memory\n", dev->bus_id);
 		return -ENOMEM;
+	}
 
 	par = info->par;
 	dev_set_drvdata(dev, info);
 
-	if (fb_alloc_cmap(&info->cmap, 256, 0) < 0)
+	if (fb_alloc_cmap(&info->cmap, 256, 0) < 0) {
+		printk(KERN_ERR "%s: Cannot allocate color map\n",
+		       dev->bus_id);
+		err = -ENOMEM;
 		goto err_alloc;
+	}
 
 	info->fbops = &pmagbafb_ops;
 	info->fix = pmagbafb_fix;
@@ -166,28 +173,41 @@ static int __init pmagbafb_probe(struct 
 	/* Request the I/O MEM resource.  */
 	start = tdev->resource.start;
 	len = tdev->resource.end - start + 1;
-	if (!request_mem_region(start, len, dev->bus_id))
+	if (!request_mem_region(start, len, dev->bus_id)) {
+		printk(KERN_ERR "%s: Cannot reserve FB region\n", dev->bus_id);
+		err = -EBUSY;
 		goto err_cmap;
+	}
 
 	/* MMIO mapping setup.  */
 	info->fix.mmio_start = start;
 	par->mmio = ioremap_nocache(info->fix.mmio_start, info->fix.mmio_len);
-	if (!par->mmio)
+	if (!par->mmio) {
+		printk(KERN_ERR "%s: Cannot map MMIO\n", dev->bus_id);
+		err = -ENOMEM;
 		goto err_resource;
+	}
 	par->dac = par->mmio + PMAG_BA_BT459;
 
 	/* Frame buffer mapping setup.  */
 	info->fix.smem_start = start + PMAG_BA_FBMEM;
 	info->screen_base = ioremap_nocache(info->fix.smem_start,
 					    info->fix.smem_len);
-	if (!info->screen_base)
+	if (!info->screen_base) {
+		printk(KERN_ERR "%s: Cannot map FB\n", dev->bus_id);
+		err = -ENOMEM;
 		goto err_mmio_map;
+	}
 	info->screen_size = info->fix.smem_len;
 
 	pmagbafb_erase_cursor(info);
 
-	if (register_framebuffer(info) < 0)
+	err = register_framebuffer(info);
+	if (err < 0) {
+		printk(KERN_ERR "%s: Cannot register framebuffer\n",
+		       dev->bus_id);
 		goto err_smem_map;
+	}
 
 	get_device(dev);