mmc: conditional scr sysfs entry

Index: linux-wbsd/drivers/mmc/mmc_sysfs.c
===================================================================
@@ -46,7 +46,6 @@
 static struct device_attribute mmc_dev_attrs[] = {
 	MMC_ATTR_RO(cid),
 	MMC_ATTR_RO(csd),
-	MMC_ATTR_RO(scr),
 	MMC_ATTR_RO(date),
 	MMC_ATTR_RO(fwrev),
 	MMC_ATTR_RO(hwrev),

@@ -57,6 +56,8 @@
 	__ATTR_NULL
 };
 
+static struct device_attribute mmc_dev_attr_scr = MMC_ATTR_RO(scr);
+
 
 static void mmc_release_card(struct device *dev)
 {

@@ -207,10 +208,20 @@
  */
 int mmc_register_card(struct mmc_card *card)
 {
+	int ret;
+
 	snprintf(card->dev.bus_id, sizeof(card->dev.bus_id),
 		 "%s:%04x", card->host->host_name, card->rca);
 
-	return device_add(&card->dev);
+	ret = device_add(&card->dev);
+	if (ret == 0) {
+		if (mmc_card_sd(card)) {
+			ret = device_create_file(&card->dev, &mmc_dev_attr_scr);
+			if (ret)
+				device_del(&card->dev);
+		}
+	}
+	return ret;
 }
 
 /*

@@ -219,8 +230,12 @@
  */
 void mmc_remove_card(struct mmc_card *card)
 {
-	if (mmc_card_present(card))
+	if (mmc_card_present(card)) {
+		if (mmc_card_sd(card))
+			device_remove_file(&card->dev, &mmc_dev_attr_scr);
+
 		device_del(&card->dev);
+	}
 
 	put_device(&card->dev);
 }