drivers/video/pmag-ba-fb.c: improve diagnostics

Add error messages to the probe call.

While they may rarely trigger, they may be useful when something weird is
going on.  Also this is good style.

[akpm@linux-foundation.org: remove unneeded initialisation]
Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Cc: Mariusz Kozlowski <m.kozlowski@tuxland.pl>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 27 insertions, 7 deletions

diff --git a/drivers/video/pmag-ba-fb.c b/drivers/video/pmag-ba-fb.c
index 264d37243fad..3a3f80f65219 100644
--- a/drivers/video/pmag-ba-fb.c
+++ b/drivers/video/pmag-ba-fb.c
@@ -147,16 +147,23 @@ static int __init pmagbafb_probe(struct device *dev)
         resource_size_t start, len;
         struct fb_info *info;
         struct pmagbafb_par *par;
+        int err;
 
         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 device *dev)
         /* 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);
 
@@ -211,7 +231,7 @@ err_cmap:
 
 err_alloc:
         framebuffer_release(info);
-        return -ENXIO;
+        return err;
 }
 
 static int __exit pmagbafb_remove(struct device *dev)