1 files changed, 215 insertions, 84 deletions

diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 44d5b128911f..1bd71a598c79 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -28,6 +28,24 @@
  *              among multiple independend devices. Suggestions and initial patch
  *              from Ben Dooks <ben-mtd@fluff.org>
  *
+ *  12-05-2004  dmarlin: add workaround for Renesas AG-AND chips "disturb" issue.
+ *              Basically, any block not rewritten may lose data when surrounding blocks
+ *              are rewritten many times.  JFFS2 ensures this doesn't happen for blocks 
+ *              it uses, but the Bad Block Table(s) may not be rewritten.  To ensure they
+ *              do not lose data, force them to be rewritten when some of the surrounding
+ *              blocks are erased.  Rather than tracking a specific nearby block (which 
+ *              could itself go bad), use a page address 'mask' to select several blocks 
+ *              in the same area, and rewrite the BBT when any of them are erased.
+ *
+ *  01-03-2005  dmarlin: added support for the device recovery command sequence for Renesas 
+ *              AG-AND chips.  If there was a sudden loss of power during an erase operation,
+ *              a "device recovery" operation must be performed when power is restored
+ *              to ensure correct operation.
+ *
+ *  01-20-2005  dmarlin: added support for optional hardware specific callback routine to 
+ *              perform extra error status checks on erase and write failures.  This required
+ *              adding a wrapper function for nand_read_ecc.
+ *
  * Credits:
  *      David Woodhouse for adding multichip support  
  *      
@@ -41,7 +59,7 @@
  *      The AG-AND chips have nice features for speed improvement,
  *      which are not supported yet. Read / program 4 pages in one go.
  *
- * $Id: nand_base.c,v 1.126 2004/12/13 11:22:25 lavinen Exp $
+ * $Id: nand_base.c,v 1.146 2005/06/17 15:02:06 gleixner Exp $
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
@@ -149,17 +167,21 @@ static void nand_release_device (struct mtd_info *mtd)
 
         /* De-select the NAND device */
         this->select_chip(mtd, -1);
-        /* Do we have a hardware controller ? */
+
         if (this->controller) {
+                /* Release the controller and the chip */
                 spin_lock(&this->controller->lock);
                 this->controller->active = NULL;
+                this->state = FL_READY;
+                wake_up(&this->controller->wq);
                 spin_unlock(&this->controller->lock);
+        } else {
+                /* Release the chip */
+                spin_lock(&this->chip_lock);
+                this->state = FL_READY;
+                wake_up(&this->wq);
+                spin_unlock(&this->chip_lock);
         }
-        /* Release the chip */
-        spin_lock (&this->chip_lock);
-        this->state = FL_READY;
-        wake_up (&this->wq);
-        spin_unlock (&this->chip_lock);
 }
 
 /**
@@ -443,7 +465,8 @@ static int nand_default_block_markbad(struct mtd_info *mtd, loff_t ofs)
         
         /* Get block number */
         block = ((int) ofs) >> this->bbt_erase_shift;
-        this->bbt[block >> 2] |= 0x01 << ((block & 0x03) << 1);
+        if (this->bbt)
+                this->bbt[block >> 2] |= 0x01 << ((block & 0x03) << 1);
 
         /* Do we have a flash based bad block table ? */
         if (this->options & NAND_USE_FLASH_BBT)
@@ -466,7 +489,7 @@ static int nand_check_wp (struct mtd_info *mtd)
         struct nand_chip *this = mtd->priv;
         /* Check the WP bit */
         this->cmdfunc (mtd, NAND_CMD_STATUS, -1, -1);
-        return (this->read_byte(mtd) & 0x80) ? 0 : 1; 
+        return (this->read_byte(mtd) & NAND_STATUS_WP) ? 0 : 1; 
 }
 
 /**
@@ -490,6 +513,22 @@ static int nand_block_checkbad (struct mtd_info *mtd, loff_t ofs, int getchip, i
         return nand_isbad_bbt (mtd, ofs, allowbbt);
 }
 
+/* 
+ * Wait for the ready pin, after a command
+ * The timeout is catched later.
+ */
+static void nand_wait_ready(struct mtd_info *mtd)
+{
+        struct nand_chip *this = mtd->priv;
+        unsigned long   timeo = jiffies + 2;
+
+        /* wait until command is processed or timeout occures */
+        do {
+                if (this->dev_ready(mtd))
+                        return;
+        } while (time_before(jiffies, timeo));  
+}
+
 /**
  * nand_command - [DEFAULT] Send command to NAND device
  * @mtd:        MTD device structure
@@ -571,7 +610,7 @@ static void nand_command (struct mtd_info *mtd, unsigned command, int column, in
                 this->hwcontrol(mtd, NAND_CTL_SETCLE);
                 this->write_byte(mtd, NAND_CMD_STATUS);
                 this->hwcontrol(mtd, NAND_CTL_CLRCLE);
-                while ( !(this->read_byte(mtd) & 0x40));
+                while ( !(this->read_byte(mtd) & NAND_STATUS_READY));
                 return;
 
         /* This applies to read commands */     
@@ -585,12 +624,11 @@ static void nand_command (struct mtd_info *mtd, unsigned command, int column, in
                         return;
                 }       
         }
-        
         /* Apply this short delay always to ensure that we do wait tWB in
          * any case on any machine. */
         ndelay (100);
-        /* wait until command is processed */
-        while (!this->dev_ready(mtd));
+
+        nand_wait_ready(mtd);
 }
 
 /**
@@ -619,7 +657,7 @@ static void nand_command_lp (struct mtd_info *mtd, unsigned command, int column,
         /* Begin command latch cycle */
         this->hwcontrol(mtd, NAND_CTL_SETCLE);
         /* Write out the command to the device. */
-        this->write_byte(mtd, command);
+        this->write_byte(mtd, (command & 0xff));
         /* End command latch cycle */
         this->hwcontrol(mtd, NAND_CTL_CLRCLE);
 
@@ -647,8 +685,8 @@ static void nand_command_lp (struct mtd_info *mtd, unsigned command, int column,
         
         /* 
          * program and erase have their own busy handlers 
-         * status and sequential in needs no delay
-        */
+         * status, sequential in, and deplete1 need no delay
+         */
         switch (command) {
                         
         case NAND_CMD_CACHEDPROG:
@@ -657,8 +695,19 @@ static void nand_command_lp (struct mtd_info *mtd, unsigned command, int column,
         case NAND_CMD_ERASE2:
         case NAND_CMD_SEQIN:
         case NAND_CMD_STATUS:
+        case NAND_CMD_DEPLETE1:
                 return;
 
+        /* 
+         * read error status commands require only a short delay
+         */
+        case NAND_CMD_STATUS_ERROR:
+        case NAND_CMD_STATUS_ERROR0:
+        case NAND_CMD_STATUS_ERROR1:
+        case NAND_CMD_STATUS_ERROR2:
+        case NAND_CMD_STATUS_ERROR3:
+                udelay(this->chip_delay);
+                return;
 
         case NAND_CMD_RESET:
                 if (this->dev_ready)    
@@ -667,7 +716,7 @@ static void nand_command_lp (struct mtd_info *mtd, unsigned command, int column,
                 this->hwcontrol(mtd, NAND_CTL_SETCLE);
                 this->write_byte(mtd, NAND_CMD_STATUS);
                 this->hwcontrol(mtd, NAND_CTL_CLRCLE);
-                while ( !(this->read_byte(mtd) & 0x40));
+                while ( !(this->read_byte(mtd) & NAND_STATUS_READY));
                 return;
 
         case NAND_CMD_READ0:
@@ -690,12 +739,12 @@ static void nand_command_lp (struct mtd_info *mtd, unsigned command, int column,
                         return;
                 }       
         }
-        
+
         /* Apply this short delay always to ensure that we do wait tWB in
          * any case on any machine. */
         ndelay (100);
-        /* wait until command is processed */
-        while (!this->dev_ready(mtd));
+
+        nand_wait_ready(mtd);
 }
 
 /**
@@ -708,37 +757,34 @@ static void nand_command_lp (struct mtd_info *mtd, unsigned command, int column,
  */
 static void nand_get_device (struct nand_chip *this, struct mtd_info *mtd, int new_state)
 {
-        struct nand_chip *active = this;
-
+        struct nand_chip *active;
+        spinlock_t *lock;
+        wait_queue_head_t *wq;
         DECLARE_WAITQUEUE (wait, current);
 
-        /* 
-         * Grab the lock and see if the device is available 
-        */
+        lock = (this->controller) ? &this->controller->lock : &this->chip_lock;
+        wq = (this->controller) ? &this->controller->wq : &this->wq;
 retry:
+        active = this;
+        spin_lock(lock);
+
         /* Hardware controller shared among independend devices */
         if (this->controller) {
-                spin_lock (&this->controller->lock);
                 if (this->controller->active)
                         active = this->controller->active;
                 else
                         this->controller->active = this;
-                spin_unlock (&this->controller->lock);
         }
-        
-        if (active == this) {
-                spin_lock (&this->chip_lock);
-                if (this->state == FL_READY) {
-                        this->state = new_state;
-                        spin_unlock (&this->chip_lock);
-                        return;
-                }
-        }       
-        set_current_state (TASK_UNINTERRUPTIBLE);
-        add_wait_queue (&active->wq, &wait);
-        spin_unlock (&active->chip_lock);
-        schedule ();
-        remove_wait_queue (&active->wq, &wait);
+        if (active == this && this->state == FL_READY) {
+                this->state = new_state;
+                spin_unlock(lock);
+                return;
+        }
+        set_current_state(TASK_UNINTERRUPTIBLE);
+        add_wait_queue(wq, &wait);
+        spin_unlock(lock);
+        schedule();
+        remove_wait_queue(wq, &wait);
         goto retry;
 }
 
@@ -785,7 +831,7 @@ static int nand_wait(struct mtd_info *mtd, struct nand_chip *this, int state)
                         if (this->read_byte(mtd) & NAND_STATUS_READY)
                                 break;
                 }
-                yield ();
+                cond_resched();
         }
         status = (int) this->read_byte(mtd);
         return status;
@@ -871,8 +917,14 @@ static int nand_write_page (struct mtd_info *mtd, struct nand_chip *this, int pa
         if (!cached) {
                 /* call wait ready function */
                 status = this->waitfunc (mtd, this, FL_WRITING);
+
+                /* See if operation failed and additional status checks are available */
+                if ((status & NAND_STATUS_FAIL) && (this->errstat)) {
+                        status = this->errstat(mtd, this, FL_WRITING, status, page);
+                }
+
                 /* See if device thinks it succeeded */
-                if (status & 0x01) {
+                if (status & NAND_STATUS_FAIL) {
                         DEBUG (MTD_DEBUG_LEVEL0, "%s: " "Failed write, page 0x%08x, ", __FUNCTION__, page);
                         return -EIO;
                 }
@@ -975,7 +1027,7 @@ static int nand_verify_pages (struct mtd_info *mtd, struct nand_chip *this, int
                 if (!this->dev_ready) 
                         udelay (this->chip_delay);
                 else
-                        while (!this->dev_ready(mtd));  
+                        nand_wait_ready(mtd);
 
                 /* All done, return happy */
                 if (!numpages)
@@ -997,23 +1049,24 @@ out:
 #endif
 
 /**
- * nand_read - [MTD Interface] MTD compability function for nand_read_ecc
+ * nand_read - [MTD Interface] MTD compability function for nand_do_read_ecc
  * @mtd:        MTD device structure
  * @from:       offset to read from
  * @len:        number of bytes to read
  * @retlen:     pointer to variable to store the number of read bytes
  * @buf:        the databuffer to put data
  *
- * This function simply calls nand_read_ecc with oob buffer and oobsel = NULL
-*/
+ * This function simply calls nand_do_read_ecc with oob buffer and oobsel = NULL
+ * and flags = 0xff
+ */
 static int nand_read (struct mtd_info *mtd, loff_t from, size_t len, size_t * retlen, u_char * buf)
 {
-        return nand_read_ecc (mtd, from, len, retlen, buf, NULL, NULL);
-}                          
+        return nand_do_read_ecc (mtd, from, len, retlen, buf, NULL, &mtd->oobinfo, 0xff);
+}
 
 
 /**
- * nand_read_ecc - [MTD Interface] Read data with ECC
+ * nand_read_ecc - [MTD Interface] MTD compability function for nand_do_read_ecc
  * @mtd:        MTD device structure
  * @from:       offset to read from
  * @len:        number of bytes to read
@@ -1022,11 +1075,39 @@ static int nand_read (struct mtd_info *mtd, loff_t from, size_t len, size_t * re
  * @oob_buf:    filesystem supplied oob data buffer
  * @oobsel:     oob selection structure
  *
- * NAND read with ECC
+ * This function simply calls nand_do_read_ecc with flags = 0xff
  */
 static int nand_read_ecc (struct mtd_info *mtd, loff_t from, size_t len,
                           size_t * retlen, u_char * buf, u_char * oob_buf, struct nand_oobinfo *oobsel)
 {
+        /* use userspace supplied oobinfo, if zero */
+        if (oobsel == NULL)
+                oobsel = &mtd->oobinfo;
+        return nand_do_read_ecc(mtd, from, len, retlen, buf, oob_buf, oobsel, 0xff);
+}
+
+
+/**
+ * nand_do_read_ecc - [MTD Interface] Read data with ECC
+ * @mtd:        MTD device structure
+ * @from:       offset to read from
+ * @len:        number of bytes to read
+ * @retlen:     pointer to variable to store the number of read bytes
+ * @buf:        the databuffer to put data
+ * @oob_buf:    filesystem supplied oob data buffer (can be NULL)
+ * @oobsel:     oob selection structure
+ * @flags:      flag to indicate if nand_get_device/nand_release_device should be preformed
+ *              and how many corrected error bits are acceptable:
+ *                bits 0..7 - number of tolerable errors
+ *                bit  8    - 0 == do not get/release chip, 1 == get/release chip
+ *
+ * NAND read with ECC
+ */
+int nand_do_read_ecc (struct mtd_info *mtd, loff_t from, size_t len,
+                             size_t * retlen, u_char * buf, u_char * oob_buf, 
+                             struct nand_oobinfo *oobsel, int flags)
+{
+
         int i, j, col, realpage, page, end, ecc, chipnr, sndcmd = 1;
         int read = 0, oob = 0, ecc_status = 0, ecc_failed = 0;
         struct nand_chip *this = mtd->priv;
@@ -1051,12 +1132,9 @@ static int nand_read_ecc (struct mtd_info *mtd, loff_t from, size_t len,
         }
 
         /* Grab the lock and see if the device is available */
-        nand_get_device (this, mtd ,FL_READING);
+        if (flags & NAND_GET_DEVICE)
+                nand_get_device (this, mtd, FL_READING);
 
-        /* use userspace supplied oobinfo, if zero */
-        if (oobsel == NULL)
-                oobsel = &mtd->oobinfo;
-        
         /* Autoplace of oob data ? Use the default placement scheme */
         if (oobsel->useecc == MTD_NANDECC_AUTOPLACE)
                 oobsel = this->autooob;
@@ -1118,7 +1196,8 @@ static int nand_read_ecc (struct mtd_info *mtd, loff_t from, size_t len,
                 }       
 
                 /* get oob area, if we have no oob buffer from fs-driver */
-                if (!oob_buf || oobsel->useecc == MTD_NANDECC_AUTOPLACE)
+                if (!oob_buf || oobsel->useecc == MTD_NANDECC_AUTOPLACE ||
+                        oobsel->useecc == MTD_NANDECC_AUTOPL_USR)
                         oob_data = &this->data_buf[end];
 
                 eccsteps = this->eccsteps;
@@ -1155,7 +1234,8 @@ static int nand_read_ecc (struct mtd_info *mtd, loff_t from, size_t len,
                                         /* We calc error correction directly, it checks the hw
                                          * generator for an error, reads back the syndrome and
                                          * does the error correction on the fly */
-                                        if (this->correct_data(mtd, &data_poi[datidx], &oob_data[i], &ecc_code[i]) == -1) {
+                                        ecc_status = this->correct_data(mtd, &data_poi[datidx], &oob_data[i], &ecc_code[i]);
+                                        if ((ecc_status == -1) || (ecc_status > (flags && 0xff))) {
                                                 DEBUG (MTD_DEBUG_LEVEL0, "nand_read_ecc: " 
                                                         "Failed ECC read, page 0x%08x on chip %d\n", page, chipnr);
                                                 ecc_failed++;
@@ -1194,7 +1274,7 @@ static int nand_read_ecc (struct mtd_info *mtd, loff_t from, size_t len,
                                 p[i] = ecc_status;
                         }
                         
-                        if (ecc_status == -1) { 
+                        if ((ecc_status == -1) || (ecc_status > (flags && 0xff))) {     
                                 DEBUG (MTD_DEBUG_LEVEL0, "nand_read_ecc: " "Failed ECC read, page 0x%08x\n", page);
                                 ecc_failed++;
                         }
@@ -1206,14 +1286,14 @@ static int nand_read_ecc (struct mtd_info *mtd, loff_t from, size_t len,
                         /* without autoplace. Legacy mode used by YAFFS1 */
                         switch(oobsel->useecc) {
                         case MTD_NANDECC_AUTOPLACE:
+                        case MTD_NANDECC_AUTOPL_USR:
                                 /* Walk through the autoplace chunks */
-                                for (i = 0, j = 0; j < mtd->oobavail; i++) {
+                                for (i = 0; oobsel->oobfree[i][1]; i++) {
                                         int from = oobsel->oobfree[i][0];
                                         int num = oobsel->oobfree[i][1];
                                         memcpy(&oob_buf[oob], &oob_data[from], num);
-                                        j+= num;
+                                        oob += num;
                                 }
-                                oob += mtd->oobavail;
                                 break;
                         case MTD_NANDECC_PLACE:
                                 /* YAFFS1 legacy mode */
@@ -1239,7 +1319,7 @@ static int nand_read_ecc (struct mtd_info *mtd, loff_t from, size_t len,
                 if (!this->dev_ready) 
                         udelay (this->chip_delay);
                 else
-                        while (!this->dev_ready(mtd));  
+                        nand_wait_ready(mtd);
                         
                 if (read == len)
                         break;  
@@ -1264,7 +1344,8 @@ static int nand_read_ecc (struct mtd_info *mtd, loff_t from, size_t len,
         }
 
         /* Deselect and wake up anyone waiting on the device */
-        nand_release_device(mtd);
+        if (flags & NAND_GET_DEVICE)
+                nand_release_device(mtd);
 
         /*
          * Return success, if no ECC failures, else -EBADMSG
@@ -1337,7 +1418,7 @@ static int nand_read_oob (struct mtd_info *mtd, loff_t from, size_t len, size_t
                 if (!this->dev_ready) 
                         udelay (this->chip_delay);
                 else
-                        while (!this->dev_ready(mtd));  
+                        nand_wait_ready(mtd);
 
                 /* Read more ? */
                 if (i < len) {
@@ -1417,7 +1498,7 @@ int nand_read_raw (struct mtd_info *mtd, uint8_t *buf, loff_t from, size_t len,
                 if (!this->dev_ready) 
                         udelay (this->chip_delay);
                 else
-                        while (!this->dev_ready(mtd));  
+                        nand_wait_ready(mtd);
                         
                 /* Check, if the chip supports auto page increment */ 
                 if (!NAND_CANAUTOINCR(this) || !(page & blockcheck))
@@ -1567,6 +1648,8 @@ static int nand_write_ecc (struct mtd_info *mtd, loff_t to, size_t len,
                 oobsel = this->autooob;
                 autoplace = 1;
         }       
+        if (oobsel->useecc == MTD_NANDECC_AUTOPL_USR)
+                autoplace = 1;
 
         /* Setup variables and oob buffer */
         totalpages = len >> this->page_shift;
@@ -1733,7 +1816,7 @@ static int nand_write_oob (struct mtd_info *mtd, loff_t to, size_t len, size_t *
         status = this->waitfunc (mtd, this, FL_WRITING);
 
         /* See if device thinks it succeeded */
-        if (status & 0x01) {
+        if (status & NAND_STATUS_FAIL) {
                 DEBUG (MTD_DEBUG_LEVEL0, "nand_write_oob: " "Failed write, page 0x%08x\n", page);
                 ret = -EIO;
                 goto out;
@@ -1841,6 +1924,8 @@ static int nand_writev_ecc (struct mtd_info *mtd, const struct kvec *vecs, unsig
                 oobsel = this->autooob;
                 autoplace = 1;
         }       
+        if (oobsel->useecc == MTD_NANDECC_AUTOPL_USR)
+                autoplace = 1;
 
         /* Setup start page */
         page = (int) (to >> this->page_shift);
@@ -1987,6 +2072,7 @@ static int nand_erase (struct mtd_info *mtd, struct erase_info *instr)
         return nand_erase_nand (mtd, instr, 0);
 }
  
+#define BBT_PAGE_MASK   0xffffff3f
 /**
  * nand_erase_intern - [NAND Interface] erase block(s)
  * @mtd:        MTD device structure
@@ -1999,6 +2085,10 @@ int nand_erase_nand (struct mtd_info *mtd, struct erase_info *instr, int allowbb
 {
         int page, len, status, pages_per_block, ret, chipnr;
         struct nand_chip *this = mtd->priv;
+        int rewrite_bbt[NAND_MAX_CHIPS]={0};    /* flags to indicate the page, if bbt needs to be rewritten. */
+        unsigned int bbt_masked_page;           /* bbt mask to compare to page being erased. */
+                                                /* It is used to see if the current page is in the same */
+                                                /*   256 block group and the same bank as the bbt. */
 
         DEBUG (MTD_DEBUG_LEVEL3,
                "nand_erase: start = 0x%08x, len = %i\n", (unsigned int) instr->addr, (unsigned int) instr->len);
@@ -2044,6 +2134,13 @@ int nand_erase_nand (struct mtd_info *mtd, struct erase_info *instr, int allowbb
                 goto erase_exit;
         }
 
+        /* if BBT requires refresh, set the BBT page mask to see if the BBT should be rewritten */
+        if (this->options & BBT_AUTO_REFRESH) {
+                bbt_masked_page = this->bbt_td->pages[chipnr] & BBT_PAGE_MASK;
+        } else {
+                bbt_masked_page = 0xffffffff;   /* should not match anything */
+        }
+
         /* Loop through the pages */
         len = instr->len;
 
@@ -2066,13 +2163,26 @@ int nand_erase_nand (struct mtd_info *mtd, struct erase_info *instr, int allowbb
                 
                 status = this->waitfunc (mtd, this, FL_ERASING);
 
+                /* See if operation failed and additional status checks are available */
+                if ((status & NAND_STATUS_FAIL) && (this->errstat)) {
+                        status = this->errstat(mtd, this, FL_ERASING, status, page);
+                }
+
                 /* See if block erase succeeded */
-                if (status & 0x01) {
+                if (status & NAND_STATUS_FAIL) {
                         DEBUG (MTD_DEBUG_LEVEL0, "nand_erase: " "Failed erase, page 0x%08x\n", page);
                         instr->state = MTD_ERASE_FAILED;
                         instr->fail_addr = (page << this->page_shift);
                         goto erase_exit;
                 }
+
+                /* if BBT requires refresh, set the BBT rewrite flag to the page being erased */
+                if (this->options & BBT_AUTO_REFRESH) {
+                        if (((page & BBT_PAGE_MASK) == bbt_masked_page) && 
+                             (page != this->bbt_td->pages[chipnr])) {
+                                rewrite_bbt[chipnr] = (page << this->page_shift);
+                        }
+                }
                 
                 /* Increment page address and decrement length */
                 len -= (1 << this->phys_erase_shift);
@@ -2083,6 +2193,13 @@ int nand_erase_nand (struct mtd_info *mtd, struct erase_info *instr, int allowbb
                         chipnr++;
                         this->select_chip(mtd, -1);
                         this->select_chip(mtd, chipnr);
+
+                        /* if BBT requires refresh and BBT-PERCHIP, 
+                         *   set the BBT page mask to see if this BBT should be rewritten */
+                        if ((this->options & BBT_AUTO_REFRESH) && (this->bbt_td->options & NAND_BBT_PERCHIP)) {
+                                bbt_masked_page = this->bbt_td->pages[chipnr] & BBT_PAGE_MASK;
+                        }
+
                 }
         }
         instr->state = MTD_ERASE_DONE;
@@ -2097,6 +2214,18 @@ erase_exit:
         /* Deselect and wake up anyone waiting on the device */
         nand_release_device(mtd);
 
+        /* if BBT requires refresh and erase was successful, rewrite any selected bad block tables */
+        if ((this->options & BBT_AUTO_REFRESH) && (!ret)) {
+                for (chipnr = 0; chipnr < this->numchips; chipnr++) {
+                        if (rewrite_bbt[chipnr]) {
+                                /* update the BBT for chip */
+                                DEBUG (MTD_DEBUG_LEVEL0, "nand_erase_nand: nand_update_bbt (%d:0x%0x 0x%0x)\n", 
+                                        chipnr, rewrite_bbt[chipnr], this->bbt_td->pages[chipnr]);
+                                nand_update_bbt (mtd, rewrite_bbt[chipnr]);
+                        }
+                }
+        }
+
         /* Return more or less happy */
         return ret;
 }
@@ -2168,7 +2297,7 @@ static int nand_block_markbad (struct mtd_info *mtd, loff_t ofs)
  */
 int nand_scan (struct mtd_info *mtd, int maxchips)
 {
-        int i, j, nand_maf_id, nand_dev_id, busw;
+        int i, nand_maf_id, nand_dev_id, busw, maf_id;
         struct nand_chip *this = mtd->priv;
 
         /* Get buswidth to select the correct functions*/
@@ -2256,12 +2385,18 @@ int nand_scan (struct mtd_info *mtd, int maxchips)
                         busw = nand_flash_ids[i].options & NAND_BUSWIDTH_16;
                 }
 
+                /* Try to identify manufacturer */
+                for (maf_id = 0; nand_manuf_ids[maf_id].id != 0x0; maf_id++) {
+                        if (nand_manuf_ids[maf_id].id == nand_maf_id)
+                                break;
+                }
+
                 /* Check, if buswidth is correct. Hardware drivers should set
                  * this correct ! */
                 if (busw != (this->options & NAND_BUSWIDTH_16)) {
                         printk (KERN_INFO "NAND device: Manufacturer ID:"
                                 " 0x%02x, Chip ID: 0x%02x (%s %s)\n", nand_maf_id, nand_dev_id, 
-                                nand_manuf_ids[i].name , mtd->name);
+                                nand_manuf_ids[maf_id].name , mtd->name);
                         printk (KERN_WARNING 
                                 "NAND bus width %d instead %d bit\n", 
                                         (this->options & NAND_BUSWIDTH_16) ? 16 : 8,
@@ -2300,14 +2435,9 @@ int nand_scan (struct mtd_info *mtd, int maxchips)
                 if (mtd->oobblock > 512 && this->cmdfunc == nand_command)
                         this->cmdfunc = nand_command_lp;
                                 
-                /* Try to identify manufacturer */
-                for (j = 0; nand_manuf_ids[j].id != 0x0; j++) {
-                        if (nand_manuf_ids[j].id == nand_maf_id)
-                                break;
-                }
                 printk (KERN_INFO "NAND device: Manufacturer ID:"
                         " 0x%02x, Chip ID: 0x%02x (%s %s)\n", nand_maf_id, nand_dev_id, 
-                        nand_manuf_ids[j].name , nand_flash_ids[i].name);
+                        nand_manuf_ids[maf_id].name , nand_flash_ids[i].name);
                 break;
         }
 
@@ -2388,12 +2518,9 @@ int nand_scan (struct mtd_info *mtd, int maxchips)
         
         /* The number of bytes available for the filesystem to place fs dependend
          * oob data */
-        if (this->options & NAND_BUSWIDTH_16) {
-                mtd->oobavail = mtd->oobsize - (this->autooob->eccbytes + 2);
-                if (this->autooob->eccbytes & 0x01)
-                        mtd->oobavail--;
-        } else
-                mtd->oobavail = mtd->oobsize - (this->autooob->eccbytes + 1);
+        mtd->oobavail = 0;
+        for (i = 0; this->autooob->oobfree[i][1]; i++)
+                mtd->oobavail += this->autooob->oobfree[i][1];
 
         /* 
          * check ECC mode, default to software
@@ -2524,6 +2651,10 @@ int nand_scan (struct mtd_info *mtd, int maxchips)
         memcpy(&mtd->oobinfo, this->autooob, sizeof(mtd->oobinfo));
 
         mtd->owner = THIS_MODULE;
+        
+        /* Check, if we should skip the bad block table scan */
+        if (this->options & NAND_SKIP_BBTSCAN)
+                return 0;
 
         /* Build bad block table */
         return this->scan_bbt (mtd);
@@ -2555,8 +2686,8 @@ void nand_release (struct mtd_info *mtd)
                 kfree (this->data_buf);
 }
 
-EXPORT_SYMBOL (nand_scan);
-EXPORT_SYMBOL (nand_release);
+EXPORT_SYMBOL_GPL (nand_scan);
+EXPORT_SYMBOL_GPL (nand_release);
 
 MODULE_LICENSE ("GPL");
 MODULE_AUTHOR ("Steven J. Hill <sjhill@realitydiluted.com>, Thomas Gleixner <tglx@linutronix.de>");