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authorDavid A. Marlin <dmarlin@redhat.com>2005-01-17 18:35:25 +0000
committerThomas Gleixner <tglx@mtd.linutronix.de>2005-05-23 11:26:45 +0200
commit30f464b74b51127b9b9a170157b75c7e8e80d2c4 (patch)
tree95a9e2f352612a4bfb94a276c1eaf21b0aec8f25 /drivers
parent28a48de72b876af794853593cc1412119ada9efc (diff)
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[MTD] NAND workaround for AG-AND disturb issue. AG-AND recovery
Added workaround for Renesas AG-AND chips "disturb" issue for Bad Block Table. Added support for the device recovery command sequence for Renesas AG-AND chips. Signed-off-by: David A. Marlin <dmarlin@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/mtd/nand/nand_base.c74
1 files changed, 69 insertions, 5 deletions
diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 44d5b128911..2ac452e3ad6 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -28,6 +28,20 @@
* 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.
+ *
* Credits:
* David Woodhouse for adding multichip support
*
@@ -41,7 +55,7 @@
* 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 1.127 2005/01/17 18:35:22 dmarlin 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
@@ -619,7 +633,7 @@ 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 +661,8 @@ 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 +671,19 @@ 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)
@@ -1051,7 +1076,7 @@ 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);
+ nand_get_device (this, mtd, FL_READING);
/* use userspace supplied oobinfo, if zero */
if (oobsel == NULL)
@@ -1987,6 +2012,7 @@ 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 +2025,10 @@ 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 +2074,13 @@ 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;
@@ -2073,6 +2110,14 @@ int nand_erase_nand (struct mtd_info *mtd, struct erase_info *instr, int allowbb
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 +2128,13 @@ 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 +2149,18 @@ 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;
}