nerves_system_linkit

From d736b28a7c5f6fe7a10066699f6b0f2ed0e28fba Mon Sep 17 00:00:00 2001
From: Frank Hunleth <fhunleth@troodon-software.com>
Date: Wed, 22 Jun 2016 13:39:18 -0400
Subject: [PATCH] mmc_blk: remove max_devices variable

For unknown reasons, this variable would get corrupt between
initialization and use. It was also only this variable and adding guard
variables around it didn't change anything. Normally, I'd expect this
issue to point to a larger problem, but I couldn't find it. To work
around the corruption, I removed all of the code and data related to it.
I can't imagine ever using the feature anyway.

Signed-off-by: Frank Hunleth <fhunleth@troodon-software.com>
---
 drivers/mmc/card/block.c | 34 +++++++---------------------------
 1 file changed, 7 insertions(+), 27 deletions(-)

diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index 10ecc0a..6e8b2da 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -70,18 +70,6 @@ MODULE_ALIAS("mmc:block");
 
 static DEFINE_MUTEX(block_mutex);
 
-/*
- * The defaults come from config options but can be overriden by module
- * or bootarg options.
- */
-static int perdev_minors = CONFIG_MMC_BLOCK_MINORS;
-
-/*
- * We've only got one major, so number of mmcblk devices is
- * limited to 256 / number of minors per device.
- */
-static int max_devices;
-
 /* 256 minors, so at most 256 separate devices */
 static DECLARE_BITMAP(dev_use, 256);
 static DECLARE_BITMAP(name_use, 256);
@@ -129,9 +117,6 @@ enum {
 	MMC_PACKED_NR_SINGLE,
 };
 
-module_param(perdev_minors, int, 0444);
-MODULE_PARM_DESC(perdev_minors, "Minors numbers to allocate per device");
-
 static inline int mmc_blk_part_switch(struct mmc_card *card,
 				      struct mmc_blk_data *md);
 static int get_card_status(struct mmc_card *card, u32 *status, int retries);
@@ -167,10 +152,10 @@ static struct mmc_blk_data *mmc_blk_get(struct gendisk *disk)
 static inline int mmc_get_devidx(struct gendisk *disk)
 {
 	int devmaj = MAJOR(disk_devt(disk));
-	int devidx = MINOR(disk_devt(disk)) / perdev_minors;
+	int devidx = MINOR(disk_devt(disk)) / CONFIG_MMC_BLOCK_MINORS;
 
 	if (!devmaj)
-		devidx = disk->first_minor / perdev_minors;
+		devidx = disk->first_minor / CONFIG_MMC_BLOCK_MINORS;
 	return devidx;
 }
 
@@ -2096,8 +2081,8 @@ static struct mmc_blk_data *mmc_blk_alloc_req(struct mmc_card *card,
 	struct mmc_blk_data *md;
 	int devidx, ret;
 
-	devidx = find_first_zero_bit(dev_use, max_devices);
-	if (devidx >= max_devices)
+	devidx = find_first_zero_bit(dev_use, (256 / CONFIG_MMC_BLOCK_MINORS));
+	if (devidx >= (256 / CONFIG_MMC_BLOCK_MINORS))
 		return ERR_PTR(-ENOSPC);
 	__set_bit(devidx, dev_use);
 
@@ -2114,7 +2099,7 @@ static struct mmc_blk_data *mmc_blk_alloc_req(struct mmc_card *card,
 	 * index anymore so we keep track of a name index.
 	 */
 	if (!subname) {
-		md->name_idx = find_first_zero_bit(name_use, max_devices);
+		md->name_idx = find_first_zero_bit(name_use, (256 / CONFIG_MMC_BLOCK_MINORS));
 		__set_bit(md->name_idx, name_use);
 	} else
 		md->name_idx = ((struct mmc_blk_data *)
@@ -2128,7 +2113,7 @@ static struct mmc_blk_data *mmc_blk_alloc_req(struct mmc_card *card,
 	 */
 	md->read_only = mmc_blk_readonly(card);
 
-	md->disk = alloc_disk(perdev_minors);
+	md->disk = alloc_disk(CONFIG_MMC_BLOCK_MINORS);
 	if (md->disk == NULL) {
 		ret = -ENOMEM;
 		goto err_kfree;
@@ -2146,7 +2131,7 @@ static struct mmc_blk_data *mmc_blk_alloc_req(struct mmc_card *card,
 	md->queue.data = md;
 
 	md->disk->major	= MMC_BLOCK_MAJOR;
-	md->disk->first_minor = devidx * perdev_minors;
+	md->disk->first_minor = devidx * CONFIG_MMC_BLOCK_MINORS;
 	md->disk->fops = &mmc_bdops;
 	md->disk->private_data = md;
 	md->disk->queue = md->queue.queue;
@@ -2576,11 +2561,6 @@ static int __init mmc_blk_init(void)
 {
 	int res;
 
-	if (perdev_minors != CONFIG_MMC_BLOCK_MINORS)
-		pr_info("mmcblk: using %d minors per device\n", perdev_minors);
-
-	max_devices = 256 / perdev_minors;
-
 	res = register_blkdev(MMC_BLOCK_MAJOR, "mmc");
 	if (res)
 		goto out;
-- 
2.5.0