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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>
hifive-unleashed-5.1
David A. Marlin 2005-01-17 18:35:25 +00:00 committed by Thomas Gleixner
parent 28a48de72b
commit 30f464b74b
1 changed files with 69 additions and 5 deletions
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74
drivers/mtd/nand/nand_base.c
View File

@ -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;
}