mtd: cfi_cmdset_0002: add 0xFF intolerance for M29W128G

The M29W128G Numonyx flash devices are intolerant to any 0xFF command:
in the Cfi_util.c the function cfi_qry_mode_off() (that resets the device
after the autoselect mode) must have a 0xF0 command after the 0xFF command.
This fix solves also the cause of the fixup_M29W128G_write_buffer() fix,
that can be removed now.
The following patch applies to 2.6.30 kernel.
Signed-off-by: Massimo Cirillo <maxcir@gmail.com>
Acked-by: Alexey Korolev <akorolev@infradead.org>
Cc: stable@kernel.org
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

drivers/mtd/chips/cfi_cmdset_0002.c

@@ -282,16 +282,6 @@ static void fixup_s29gl032n_sectors(struct mtd_info *mtd, void *param)
 	}
 }
 
-static void fixup_M29W128G_write_buffer(struct mtd_info *mtd, void *param)
-{
-	struct map_info *map = mtd->priv;
-	struct cfi_private *cfi = map->fldrv_priv;
-	if (cfi->cfiq->BufWriteTimeoutTyp) {
-		pr_warning("Don't use write buffer on ST flash M29W128G\n");
-		cfi->cfiq->BufWriteTimeoutTyp = 0;
-	}
-}
-
 static struct cfi_fixup cfi_fixup_table[] = {
 	{ CFI_MFR_ATMEL, CFI_ID_ANY, fixup_convert_atmel_pri, NULL },
 #ifdef AMD_BOOTLOC_BUG
@@ -308,7 +298,6 @@ static struct cfi_fixup cfi_fixup_table[] = {
 	{ CFI_MFR_AMD, 0x1301, fixup_s29gl064n_sectors, NULL, },
 	{ CFI_MFR_AMD, 0x1a00, fixup_s29gl032n_sectors, NULL, },
 	{ CFI_MFR_AMD, 0x1a01, fixup_s29gl032n_sectors, NULL, },
-	{ CFI_MFR_ST,  0x227E, fixup_M29W128G_write_buffer, NULL, },
 #if !FORCE_WORD_WRITE
 	{ CFI_MFR_ANY, CFI_ID_ANY, fixup_use_write_buffers, NULL, },
 #endif

drivers/mtd/chips/cfi_util.c

@@ -81,6 +81,10 @@ void __xipram cfi_qry_mode_off(uint32_t base, struct map_info *map,
 {
 	cfi_send_gen_cmd(0xF0, 0, base, map, cfi, cfi->device_type, NULL);
 	cfi_send_gen_cmd(0xFF, 0, base, map, cfi, cfi->device_type, NULL);
+	/* M29W128G flashes require an additional reset command
+	   when exit qry mode */
+	if ((cfi->mfr == CFI_MFR_ST) && (cfi->id == 0x227E || cfi->id == 0x7E))
+		cfi_send_gen_cmd(0xF0, 0, base, map, cfi, cfi->device_type, NULL);
 }
 EXPORT_SYMBOL_GPL(cfi_qry_mode_off);