sh: dma-sysfs fixes.

Handle the case where no registered DMACs exist somewhat more
gracefully. While we're at it, check for sysdev_create_file()
failing.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

arch/sh/drivers/dma/dma-sysfs.c

@@ -3,7 +3,7 @@
  *
  * sysfs interface for SH DMA API
  *
- * Copyright (C) 2004, 2005  Paul Mundt
+ * Copyright (C) 2004 - 2006  Paul Mundt
  *
  * This file is subject to the terms and conditions of the GNU General Public
  * License.  See the file "COPYING" in the main directory of this archive
@@ -21,7 +21,6 @@
 static struct sysdev_class dma_sysclass = {
 	set_kset_name("dma"),
 };
-
 EXPORT_SYMBOL(dma_sysclass);
 
 static ssize_t dma_show_devices(struct sys_device *dev, char *buf)
@@ -31,7 +30,10 @@ static ssize_t dma_show_devices(struct sys_device *dev, char *buf)
 
 	for (i = 0; i < MAX_DMA_CHANNELS; i++) {
 		struct dma_info *info = get_dma_info(i);
-		struct dma_channel *channel = &info->channels[i];
+		struct dma_channel *channel = get_dma_channel(i);
+
+		if (unlikely(!info) || !channel)
+			continue;
 
 		len += sprintf(buf + len, "%2d: %14s    %s\n",
 			       channel->chan, info->name,
@@ -125,11 +127,16 @@ int dma_create_sysfs_files(struct dma_channel *chan, struct dma_info *info)
 	if (ret)
 		return ret;
 
-	sysdev_create_file(dev, &attr_dev_id);
-	sysdev_create_file(dev, &attr_count);
-	sysdev_create_file(dev, &attr_mode);
-	sysdev_create_file(dev, &attr_flags);
-	sysdev_create_file(dev, &attr_config);
+	ret |= sysdev_create_file(dev, &attr_dev_id);
+	ret |= sysdev_create_file(dev, &attr_count);
+	ret |= sysdev_create_file(dev, &attr_mode);
+	ret |= sysdev_create_file(dev, &attr_flags);
+	ret |= sysdev_create_file(dev, &attr_config);
+
+	if (unlikely(ret)) {
+		dev_err(&info->pdev->dev, "Failed creating attrs\n");
+		return ret;
+	}
 
 	snprintf(name, sizeof(name), "dma%d", chan->chan);
 	return sysfs_create_link(&info->pdev->dev.kobj, &dev->kobj, name);