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Commit fb4a90bf authored by Eric W. Biedermann's avatar Eric W. Biedermann Committed by Thomas Gleixner
Browse files

[MTD] CFI-0002 - Improve error checking 



Check for errors besides infinite loops when writing and erasing.

Signed-off-by: default avatarEric W. Biederman <ebiederman@lnxi.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 6da70124

drivers/mtd/chips/cfi_cmdset_0002.c

+67 −32
Original line number Diff line number Diff line
@@ -13,7 +13,7 @@ 
 *

 * This code is GPL

 *

 * $Id: cfi_cmdset_0002.c,v 1.114 2004/12/11 15:43:53 dedekind Exp $

 * $Id: cfi_cmdset_0002.c,v 1.115 2005/05/20 03:28:23 eric Exp $

 *

 */
@@ -43,6 +43,7 @@ 
#define MANUFACTURER_AMD	0x0001

#define MANUFACTURER_SST	0x00BF

#define SST49LF004B	        0x0060

#define SST49LF008A		0x005a



static int cfi_amdstd_read (struct mtd_info *, loff_t, size_t, size_t *, u_char *);

static int cfi_amdstd_write_words(struct mtd_info *, loff_t, size_t, size_t *, const u_char *);
@@ -191,6 +192,7 @@ static struct cfi_fixup cfi_fixup_table[] = { 
};

static struct cfi_fixup jedec_fixup_table[] = {

	{ MANUFACTURER_SST, SST49LF004B, fixup_use_fwh_lock, NULL, },

	{ MANUFACTURER_SST, SST49LF008A, fixup_use_fwh_lock, NULL, },

	{ 0, 0, NULL, NULL }

};
@@ -401,6 +403,32 @@ static int chip_ready(struct map_info *map, unsigned long addr) 
	return map_word_equal(map, d, t);

}



/*

 * Return true if the chip is ready and has the correct value.

 *

 * Ready is one of: read mode, query mode, erase-suspend-read mode (in any

 * non-suspended sector) and it is indicated by no bits toggling.

 *

 * Error are indicated by toggling bits or bits held with the wrong value,

 * or with bits toggling.

 *

 * Note that anything more complicated than checking if no bits are toggling

 * (including checking DQ5 for an error status) is tricky to get working

 * correctly and is therefore not done	(particulary with interleaved chips

 * as each chip must be checked independantly of the others).

 *

 */

static int chip_good(struct map_info *map, unsigned long addr, map_word expected)

{

	map_word oldd, curd;



	oldd = map_read(map, addr);

	curd = map_read(map, addr);



	return	map_word_equal(map, oldd, curd) && 

		map_word_equal(map, curd, expected);

}



static int get_chip(struct map_info *map, struct flchip *chip, unsigned long adr, int mode)

{

	DECLARE_WAITQUEUE(wait, current);
@@ -765,26 +793,29 @@ static int do_write_oneword(struct map_info *map, struct flchip *chip, unsigned 
		}



		if (chip_ready(map, adr))

			goto op_done;

			break;



		if (time_after(jiffies, timeo))

		if (time_after(jiffies, timeo)) {

			printk(KERN_WARNING "MTD %s(): software timeout\n", __func__);

                        break;

		}



		/* Latency issues. Drop the lock, wait a while and retry */

		cfi_spin_unlock(chip->mutex);

		cfi_udelay(1);

		cfi_spin_lock(chip->mutex);

	}



	printk(KERN_WARNING "MTD %s(): software timeout\n", __func__);



	/* Did we succeed? */

	if (!chip_good(map, adr, datum)) {

		/* reset on all failures. */

		map_write( map, CMD(0xF0), chip->start );

		/* FIXME - should have reset delay before continuing */



		if (++retry_cnt <= MAX_WORD_RETRIES) 

			goto retry;



		ret = -EIO;

	}

 op_done:

	chip->state = FL_READY;

	put_chip(map, chip, adr);
@@ -1187,10 +1218,13 @@ static inline int do_erase_chip(struct map_info *map, struct flchip *chip) 
		}



		if (chip_ready(map, adr))

			goto op_done;

			break;



		if (time_after(jiffies, timeo))

		if (time_after(jiffies, timeo)) {

			printk(KERN_WARNING "MTD %s(): software timeout\n",

				__func__ );

			break;

		}



		/* Latency issues. Drop the lock, wait a while and retry */

		cfi_spin_unlock(chip->mutex);
@@ -1198,16 +1232,15 @@ static inline int do_erase_chip(struct map_info *map, struct flchip *chip) 
		schedule_timeout(1);

		cfi_spin_lock(chip->mutex);

	}



	printk(KERN_WARNING "MTD %s(): software timeout\n",

	       __func__ );



	/* Did we succeed? */

	if (!chip_good(map, adr, map_word_ff(map))) {

		/* reset on all failures. */

		map_write( map, CMD(0xF0), chip->start );

		/* FIXME - should have reset delay before continuing */



		ret = -EIO;

 op_done:

	}



	chip->state = FL_READY;

	put_chip(map, chip, adr);

	cfi_spin_unlock(chip->mutex);
@@ -1272,10 +1305,13 @@ static inline int do_erase_oneblock(struct map_info *map, struct flchip *chip, u 
		}



		if (chip_ready(map, adr))

			goto op_done;

			break;



		if (time_after(jiffies, timeo))

		if (time_after(jiffies, timeo)) {

			printk(KERN_WARNING "MTD %s(): software timeout\n",

				__func__ );

			break;

		}



		/* Latency issues. Drop the lock, wait a while and retry */

		cfi_spin_unlock(chip->mutex);
@@ -1283,16 +1319,15 @@ static inline int do_erase_oneblock(struct map_info *map, struct flchip *chip, u 
		schedule_timeout(1);

		cfi_spin_lock(chip->mutex);

	}

	

	printk(KERN_WARNING "MTD %s(): software timeout\n",

	       __func__ );

	

	/* Did we succeed? */

	if (chip_good(map, adr, map_word_ff(map))) {

		/* reset on all failures. */

		map_write( map, CMD(0xF0), chip->start );

		/* FIXME - should have reset delay before continuing */



		ret = -EIO;

 op_done:

	}



	chip->state = FL_READY;

	put_chip(map, chip, adr);

	cfi_spin_unlock(chip->mutex);