diff --git a/drivers/mtd/chips/cfi_cmdset_0002.c b/drivers/mtd/chips/cfi_cmdset_0002.c
index 6561b14..590fb26 100644
--- a/drivers/mtd/chips/cfi_cmdset_0002.c
+++ b/drivers/mtd/chips/cfi_cmdset_0002.c
@@ -37,6 +37,7 @@
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/cfi.h>
 #include <linux/mtd/xip.h>
+#include <linux/mtd/exp_lock.h>
 
 #define AMD_BOOTLOC_BUG
 #define FORCE_WORD_WRITE 0
@@ -670,8 +671,12 @@
 				return -EIO;
 			}
 			mutex_unlock(&chip->mutex);
+			/* mutex to prevent concurrent NOR/NAND access on the EXP bus */
+			mutex_unlock(&exp_bus_lock);
 			cfi_udelay(1);
 			mutex_lock(&chip->mutex);
+			/* mutex to prevent concurrent NOR/NAND access on the EXP bus */
+			mutex_lock(&exp_bus_lock);
 			/* Someone else might have been playing with it. */
 			goto retry;
 		}
@@ -714,8 +719,12 @@
 			}
 
 			mutex_unlock(&chip->mutex);
+			/* mutex to prevent concurrent NOR/NAND access on the EXP bus */
+			mutex_unlock(&exp_bus_lock);
 			cfi_udelay(1);
 			mutex_lock(&chip->mutex);
+			/* mutex to prevent concurrent NOR/NAND access on the EXP bus */
+			mutex_lock(&exp_bus_lock);
 			/* Nobody will touch it while it's in state FL_ERASE_SUSPENDING.
 			   So we can just loop here. */
 		}
@@ -744,9 +753,13 @@
 		set_current_state(TASK_UNINTERRUPTIBLE);
 		add_wait_queue(&chip->wq, &wait);
 		mutex_unlock(&chip->mutex);
+		/* mutex to prevent concurrent NOR/NAND access on the EXP bus */
+		mutex_unlock(&exp_bus_lock);
 		schedule();
 		remove_wait_queue(&chip->wq, &wait);
 		mutex_lock(&chip->mutex);
+		/* mutex to prevent concurrent NOR/NAND access on the EXP bus */
+		mutex_lock(&exp_bus_lock);
 		goto resettime;
 	}
 }
@@ -878,6 +891,8 @@
 			xip_iprefetch();
 			local_irq_enable();
 			mutex_unlock(&chip->mutex);
+			/* mutex to prevent concurrent NOR/NAND access on the EXP bus */
+			mutex_unlock(&exp_bus_lock);
 			xip_iprefetch();
 			cond_resched();
 
@@ -888,14 +903,20 @@
 			 * until it's done.
 			 */
 			mutex_lock(&chip->mutex);
+			/* mutex to prevent concurrent NOR/NAND access on the EXP bus */
+			mutex_lock(&exp_bus_lock);
 			while (chip->state != FL_XIP_WHILE_ERASING) {
 				DECLARE_WAITQUEUE(wait, current);
 				set_current_state(TASK_UNINTERRUPTIBLE);
 				add_wait_queue(&chip->wq, &wait);
 				mutex_unlock(&chip->mutex);
+				/* mutex to prevent concurrent NOR/NAND access on the EXP bus */
+				mutex_unlock(&exp_bus_lock);
 				schedule();
 				remove_wait_queue(&chip->wq, &wait);
 				mutex_lock(&chip->mutex);
+				/* mutex to prevent concurrent NOR/NAND access on the EXP bus */
+				mutex_lock(&exp_bus_lock);
 			}
 			/* Disallow XIP again */
 			local_irq_disable();
@@ -958,16 +979,20 @@
 #define UDELAY(map, chip, adr, usec)  \
 do {  \
 	mutex_unlock(&chip->mutex);  \
+	mutex_unlock(&exp_bus_lock); \
 	cfi_udelay(usec);  \
 	mutex_lock(&chip->mutex);  \
+	mutex_lock(&exp_bus_lock); \
 } while (0)
 
 #define INVALIDATE_CACHE_UDELAY(map, chip, adr, len, usec)  \
 do {  \
 	mutex_unlock(&chip->mutex);  \
+	mutex_unlock(&exp_bus_lock); \
 	INVALIDATE_CACHED_RANGE(map, adr, len);  \
 	cfi_udelay(usec);  \
 	mutex_lock(&chip->mutex);  \
+	mutex_lock(&exp_bus_lock); \
 } while (0)
 
 #endif
@@ -984,9 +1009,14 @@
 	cmd_addr = adr & ~(map_bankwidth(map)-1);
 
 	mutex_lock(&chip->mutex);
+	// lock mutex to prevent simultaneous NAND and NOR access to Comcerto2000 EXP bus
+	mutex_lock(&exp_bus_lock);
+
 	ret = get_chip(map, chip, cmd_addr, FL_READY);
 	if (ret) {
 		mutex_unlock(&chip->mutex);
+		// unlock mutex to prevent simultaneous NAND and NOR access to Comcerto2000 EXP bus
+		mutex_unlock(&exp_bus_lock);
 		return ret;
 	}
 
@@ -1000,6 +1030,8 @@
 	put_chip(map, chip, cmd_addr);
 
 	mutex_unlock(&chip->mutex);
+	// unlock mutex to prevent simultaneous NAND and NOR access to Comcerto2000 EXP bus
+	mutex_unlock(&exp_bus_lock);
 	return 0;
 }
 
@@ -1054,12 +1086,16 @@
 
  retry:
 	mutex_lock(&chip->mutex);
+	// lock mutex to prevent simultaneous NAND and NOR access to Comcerto2000 EXP bus
+	mutex_lock(&exp_bus_lock);
 
 	if (chip->state != FL_READY){
 		set_current_state(TASK_UNINTERRUPTIBLE);
 		add_wait_queue(&chip->wq, &wait);
 
 		mutex_unlock(&chip->mutex);
+		// unlock mutex to prevent simultaneous NAND and NOR access to Comcerto2000 EXP bus
+		mutex_unlock(&exp_bus_lock);
 
 		schedule();
 		remove_wait_queue(&chip->wq, &wait);
@@ -1085,6 +1121,8 @@
 
 	wake_up(&chip->wq);
 	mutex_unlock(&chip->mutex);
+	// unlock mutex to prevent simultaneous NAND and NOR access to Comcerto2000 EXP bus
+	mutex_unlock(&exp_bus_lock);
 
 	return 0;
 }
@@ -1154,9 +1192,15 @@
 	adr += chip->start;
 
 	mutex_lock(&chip->mutex);
+	// lock mutex to prevent simultaneous NAND and NOR access to Comcerto2000 EXP bus
+	mutex_lock(&exp_bus_lock);
+
+
 	ret = get_chip(map, chip, adr, FL_WRITING);
 	if (ret) {
 		mutex_unlock(&chip->mutex);
+		// unlock mutex to prevent simultaneous NAND and NOR access to Comcerto2000 EXP bus
+		mutex_unlock(&exp_bus_lock);
 		return ret;
 	}
 
@@ -1200,10 +1244,14 @@
 			set_current_state(TASK_UNINTERRUPTIBLE);
 			add_wait_queue(&chip->wq, &wait);
 			mutex_unlock(&chip->mutex);
+			// unlock mutex to prevent simultaneous NAND and NOR access to Comcerto2000 EXP bus
+			mutex_unlock(&exp_bus_lock);
 			schedule();
 			remove_wait_queue(&chip->wq, &wait);
 			timeo = jiffies + (HZ / 2); /* FIXME */
 			mutex_lock(&chip->mutex);
+			// lock mutex to prevent simultaneous NAND and NOR access to Comcerto2000 EXP bus
+			mutex_lock(&exp_bus_lock);
 			continue;
 		}
 
@@ -1236,6 +1284,8 @@
 	chip->state = FL_READY;
 	put_chip(map, chip, adr);
 	mutex_unlock(&chip->mutex);
+	// unlock mutex to prevent simultaneous NAND and NOR access to Comcerto2000 EXP bus
+	mutex_unlock(&exp_bus_lock);
 
 	return ret;
 }
@@ -1389,9 +1439,14 @@
 	cmd_adr = adr;
 
 	mutex_lock(&chip->mutex);
+	// lock mutex to prevent simultaneous NAND and NOR access to Comcerto2000 EXP bus
+	mutex_lock(&exp_bus_lock);
+
 	ret = get_chip(map, chip, adr, FL_WRITING);
 	if (ret) {
 		mutex_unlock(&chip->mutex);
+		// unlock mutex to prevent simultaneous NAND and NOR access to Comcerto2000 EXP bus
+		mutex_unlock(&exp_bus_lock);
 		return ret;
 	}
 
@@ -1410,6 +1465,9 @@
 	/* Write Buffer Load */
 	map_write(map, CMD(0x25), cmd_adr);
 
+	/* patch from https://dev.openwrt.org/browser/trunk/target/linux/generic/patches-3.2/475-mtd_cfi_cmdset_0002-add-buffer-write-cmd-timeout.patch?rev=31000 */
+	(void) map_read(map, cmd_adr);
+
 	chip->state = FL_WRITING_TO_BUFFER;
 
 	/* Write length of data to come */
@@ -1446,10 +1504,14 @@
 			set_current_state(TASK_UNINTERRUPTIBLE);
 			add_wait_queue(&chip->wq, &wait);
 			mutex_unlock(&chip->mutex);
+			// unlock mutex to prevent simultaneous NAND and NOR access to Comcerto2000 EXP bus
+			mutex_unlock(&exp_bus_lock);
 			schedule();
 			remove_wait_queue(&chip->wq, &wait);
 			timeo = jiffies + (HZ / 2); /* FIXME */
 			mutex_lock(&chip->mutex);
+			// lock mutex to prevent simultaneous NAND and NOR access to Comcerto2000 EXP bus
+			mutex_lock(&exp_bus_lock);
 			continue;
 		}
 
@@ -1490,6 +1552,8 @@
 	chip->state = FL_READY;
 	put_chip(map, chip, adr);
 	mutex_unlock(&chip->mutex);
+	// unlock mutex to prevent simultaneous NAND and NOR access to Comcerto2000 EXP bus
+	mutex_unlock(&exp_bus_lock);
 
 	return ret;
 }
@@ -1590,9 +1654,14 @@
 	adr = cfi->addr_unlock1;
 
 	mutex_lock(&chip->mutex);
+	// lock mutex to prevent simultaneous NAND and NOR access to Comcerto2000 EXP bus
+	mutex_lock(&exp_bus_lock);
+
 	ret = get_chip(map, chip, adr, FL_WRITING);
 	if (ret) {
 		mutex_unlock(&chip->mutex);
+		// unlock mutex to prevent simultaneous NAND and NOR access to Comcerto2000 EXP bus
+		mutex_unlock(&exp_bus_lock);
 		return ret;
 	}
 
@@ -1626,9 +1695,13 @@
 			set_current_state(TASK_UNINTERRUPTIBLE);
 			add_wait_queue(&chip->wq, &wait);
 			mutex_unlock(&chip->mutex);
+			// unlock mutex to prevent simultaneous NAND and NOR access to Comcerto2000 EXP bus
+			mutex_unlock(&exp_bus_lock);
 			schedule();
 			remove_wait_queue(&chip->wq, &wait);
 			mutex_lock(&chip->mutex);
+			// lock mutex to prevent simultaneous NAND and NOR access to Comcerto2000 EXP bus
+			mutex_lock(&exp_bus_lock);
 			continue;
 		}
 		if (chip->erase_suspended) {
@@ -1663,6 +1736,8 @@
 	xip_enable(map, chip, adr);
 	put_chip(map, chip, adr);
 	mutex_unlock(&chip->mutex);
+	// unlock mutex to prevent simultaneous NAND and NOR access to Comcerto2000 EXP bus
+	mutex_unlock(&exp_bus_lock);
 
 	return ret;
 }
@@ -1678,9 +1753,14 @@
 	adr += chip->start;
 
 	mutex_lock(&chip->mutex);
+	// lock mutex to prevent simultaneous NAND and NOR access to Comcerto2000 EXP bus
+	mutex_lock(&exp_bus_lock);
+
 	ret = get_chip(map, chip, adr, FL_ERASING);
 	if (ret) {
 		mutex_unlock(&chip->mutex);
+		// unlock mutex to prevent simultaneous NAND and NOR access to Comcerto2000 EXP bus
+		mutex_unlock(&exp_bus_lock);
 		return ret;
 	}
 
@@ -1714,9 +1794,13 @@
 			set_current_state(TASK_UNINTERRUPTIBLE);
 			add_wait_queue(&chip->wq, &wait);
 			mutex_unlock(&chip->mutex);
+			// unlock mutex to prevent simultaneous NAND and NOR access to Comcerto2000 EXP bus
+			mutex_unlock(&exp_bus_lock);
 			schedule();
 			remove_wait_queue(&chip->wq, &wait);
 			mutex_lock(&chip->mutex);
+			// lock mutex to prevent simultaneous NAND and NOR access to Comcerto2000 EXP bus
+			mutex_lock(&exp_bus_lock);
 			continue;
 		}
 		if (chip->erase_suspended) {
@@ -1753,6 +1837,9 @@
 	chip->state = FL_READY;
 	put_chip(map, chip, adr);
 	mutex_unlock(&chip->mutex);
+	// unlock mutex to prevent simultaneous NAND and NOR access to Comcerto2000 EXP bus
+	mutex_unlock(&exp_bus_lock);
+
 	return ret;
 }
 
@@ -1805,6 +1892,9 @@
 	int ret;
 
 	mutex_lock(&chip->mutex);
+	// lock mutex to prevent simultaneous NAND and NOR access to Comcerto2000 EXP bus
+	mutex_lock(&exp_bus_lock);
+
 	ret = get_chip(map, chip, adr + chip->start, FL_LOCKING);
 	if (ret)
 		goto out_unlock;
@@ -1830,6 +1920,8 @@
 
 out_unlock:
 	mutex_unlock(&chip->mutex);
+	// unlock mutex to prevent simultaneous NAND and NOR access to Comcerto2000 EXP bus
+	mutex_unlock(&exp_bus_lock);
 	return ret;
 }
 
@@ -1840,6 +1932,9 @@
 	int ret;
 
 	mutex_lock(&chip->mutex);
+	// lock mutex to prevent simultaneous NAND and NOR access to Comcerto2000 EXP bus
+	mutex_lock(&exp_bus_lock);
+
 	ret = get_chip(map, chip, adr + chip->start, FL_UNLOCKING);
 	if (ret)
 		goto out_unlock;
@@ -1857,6 +1952,8 @@
 
 out_unlock:
 	mutex_unlock(&chip->mutex);
+	// unlock mutex to prevent simultaneous NAND and NOR access to Comcerto2000 EXP bus
+	mutex_unlock(&exp_bus_lock);
 	return ret;
 }
 
@@ -1885,6 +1982,8 @@
 
 	retry:
 		mutex_lock(&chip->mutex);
+		// lock mutex to prevent simultaneous NAND and NOR access to Comcerto2000 EXP bus
+		mutex_lock(&exp_bus_lock);
 
 		switch(chip->state) {
 		case FL_READY:
@@ -1899,6 +1998,8 @@
 			 */
 		case FL_SYNCING:
 			mutex_unlock(&chip->mutex);
+			// unlock mutex to prevent simultaneous NAND and NOR access to Comcerto2000 EXP bus
+			mutex_unlock(&exp_bus_lock);
 			break;
 
 		default:
@@ -1907,6 +2008,8 @@
 			add_wait_queue(&chip->wq, &wait);
 
 			mutex_unlock(&chip->mutex);
+			// unlock mutex to prevent simultaneous NAND and NOR access to Comcerto2000 EXP bus
+			mutex_unlock(&exp_bus_lock);
 
 			schedule();
 
@@ -1922,12 +2025,16 @@
 		chip = &cfi->chips[i];
 
 		mutex_lock(&chip->mutex);
+		// lock mutex to prevent simultaneous NAND and NOR access to Comcerto2000 EXP bus
+		mutex_lock(&exp_bus_lock);
 
 		if (chip->state == FL_SYNCING) {
 			chip->state = chip->oldstate;
 			wake_up(&chip->wq);
 		}
 		mutex_unlock(&chip->mutex);
+		// unlock mutex to prevent simultaneous NAND and NOR access to Comcerto2000 EXP bus
+		mutex_unlock(&exp_bus_lock);
 	}
 }
 
@@ -1944,6 +2051,8 @@
 		chip = &cfi->chips[i];
 
 		mutex_lock(&chip->mutex);
+		// lock mutex to prevent simultaneous NAND and NOR access to Comcerto2000 EXP bus
+		mutex_lock(&exp_bus_lock);
 
 		switch(chip->state) {
 		case FL_READY:
@@ -1964,6 +2073,9 @@
 			break;
 		}
 		mutex_unlock(&chip->mutex);
+		// unlock mutex to prevent simultaneous NAND and NOR access to Comcerto2000 EXP bus
+		mutex_unlock(&exp_bus_lock);
+
 	}
 
 	/* Unlock the chips again */
@@ -1973,12 +2085,16 @@
 			chip = &cfi->chips[i];
 
 			mutex_lock(&chip->mutex);
+			// lock mutex to prevent simultaneous NAND and NOR access to Comcerto2000 EXP bus
+			mutex_lock(&exp_bus_lock);
 
 			if (chip->state == FL_PM_SUSPENDED) {
 				chip->state = chip->oldstate;
 				wake_up(&chip->wq);
 			}
 			mutex_unlock(&chip->mutex);
+			// unlock mutex to prevent simultaneous NAND and NOR access to Comcerto2000 EXP bus
+			mutex_unlock(&exp_bus_lock);
 		}
 	}
 
@@ -1998,6 +2114,8 @@
 		chip = &cfi->chips[i];
 
 		mutex_lock(&chip->mutex);
+		// lock mutex to prevent simultaneous NAND and NOR access to Comcerto2000 EXP bus
+		mutex_lock(&exp_bus_lock);
 
 		if (chip->state == FL_PM_SUSPENDED) {
 			chip->state = FL_READY;
@@ -2008,6 +2126,8 @@
 			printk(KERN_ERR "Argh. Chip not in PM_SUSPENDED state upon resume()\n");
 
 		mutex_unlock(&chip->mutex);
+		// unlock mutex to prevent simultaneous NAND and NOR access to Comcerto2000 EXP bus
+		mutex_unlock(&exp_bus_lock);
 	}
 }
 
@@ -2030,6 +2150,8 @@
 		chip = &cfi->chips[i];
 
 		mutex_lock(&chip->mutex);
+		// lock mutex to prevent simultaneous NAND and NOR access to Comcerto2000 EXP bus
+		mutex_lock(&exp_bus_lock);
 
 		ret = get_chip(map, chip, chip->start, FL_SHUTDOWN);
 		if (!ret) {
@@ -2039,6 +2161,8 @@
 		}
 
 		mutex_unlock(&chip->mutex);
+		// lock mutex to prevent simultaneous NAND and NOR access to Comcerto2000 EXP bus
+		mutex_unlock(&exp_bus_lock);
 	}
 
 	return 0;
diff --git a/drivers/mtd/chips/gen_probe.c b/drivers/mtd/chips/gen_probe.c
index 3b9a284..1a37000 100644
--- a/drivers/mtd/chips/gen_probe.c
+++ b/drivers/mtd/chips/gen_probe.c
@@ -11,6 +11,12 @@
 #include <linux/mtd/map.h>
 #include <linux/mtd/cfi.h>
 #include <linux/mtd/gen_probe.h>
+#include <linux/mtd/exp_lock.h>
+
+/* Define a mutex available to both comcerto NAND driver and cfi NOR flash driver */
+DEFINE_MUTEX(exp_bus_lock);
+EXPORT_SYMBOL(exp_bus_lock);
+
 
 static struct mtd_info *check_cmd_set(struct map_info *, int);
 static struct cfi_private *genprobe_ident_chips(struct map_info *map,
@@ -29,6 +35,9 @@
 	if (!cfi)
 		return NULL;
 
+	/* Init the mutex which prevents concurrent NOR and NAND accesses to C2k EXP_BUS */
+	mutex_init(&exp_bus_lock);
+
 	map->fldrv_priv = cfi;
 	/* OK we liked it. Now find a driver for the command set it talks */
 
diff --git a/drivers/mtd/nand/comcerto_nand.c b/drivers/mtd/nand/comcerto_nand.c
index 7a1c161..6c840ac 100644
--- a/drivers/mtd/nand/comcerto_nand.c
+++ b/drivers/mtd/nand/comcerto_nand.c
@@ -26,6 +26,7 @@
 #include <linux/ratelimit.h>
 #include <linux/platform_device.h>
 #include <mach/ecc.h>
+#include <linux/mtd/exp_lock.h>
 
 /*
  * MTD structure for Comcerto board
@@ -285,7 +286,7 @@
 	if (likely(!((readl_relaxed(ecc_base_addr + ECC_POLY_STAT)) & ECC_CORR_REQ))) {
 		return 0;
 	}
- 
+
 	/* Error found! Correction required */
 #if defined (CONFIG_NAND_COMCERTO_ECC_8_HW_BCH) || defined (CONFIG_NAND_COMCERTO_ECC_24_HW_BCH)
 	/* Initiate correction operation */
@@ -389,6 +390,8 @@
 	const uint8_t *p = buf;
 	uint8_t *oob = chip->oob_poi;
 
+	// lock mutex to prevent simultaneous NAND and NOR access to Comcerto2000 EXP bus
+	mutex_lock(&exp_bus_lock);
 	/* CS4 will have the option for ECC calculation */
 	writel_relaxed(ECC_CS4_SEL, ecc_base_addr + ECC_CS_SEL_CFG);
 
@@ -410,6 +413,9 @@
 	i = mtd->oobsize - (oob - chip->oob_poi);
 	if (i)
 		chip->write_buf(mtd, oob, i);
+
+	// unlock mutex to prevent simultaneous NAND and NOR access to Comcerto2000 EXP bus
+	mutex_unlock(&exp_bus_lock);
 }
 
 /** reads single page from the NAND device and will read ECC bytes from flash. A
@@ -433,6 +439,9 @@
 	uint8_t stat;
 	uint8_t *oob = nand_device->oob_poi;
 
+	// lock mutex to prevent simultaneous NAND and NOR access to Comcerto2000 EXP bus
+	mutex_lock(&exp_bus_lock);
+
 	for (; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
 
 		chip->ecc.hwctl(mtd, NAND_ECC_READ);
@@ -464,6 +473,8 @@
 	if (i)
 		chip->read_buf(mtd, oob, i);
 
+	// unlock mutex to prevent simultaneous NAND and NOR access to Comcerto2000 EXP bus
+	mutex_unlock(&exp_bus_lock);
 	return 0;
 }
 
diff --git a/include/linux/mtd/exp_lock.h b/include/linux/mtd/exp_lock.h
new file mode 100644
index 0000000..8360bc6
--- /dev/null
+++ b/include/linux/mtd/exp_lock.h
@@ -0,0 +1,25 @@
+/*
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ */
+
+#ifndef __MTD_EXP_LOCK_H__
+#define __MTD_EXP_LOCK_H__
+
+/* Define a mutex available to both comcerto NAND driver and cfi NOR flash driver */
+extern struct mutex exp_bus_lock;
+
+#endif /* __MTD_MTD_H__ */