Merge tag 'cfi/for-5.4-rc1' of https://github.com/r-vignesh/linux into mtd/for-5.4

CFI core

* Kill useless initializer in mtd_do_chip_probe()
* Fix a rare write failure seen on some cfi_cmdset_0002 compliant
  Parallel NORs
* Bunch of cleanups for cfi_cmdset_0002 driver's write functions by
  Tokunori Ikegami <ikegami.t@gmail.com>

2 files changed, 186 insertions, 113 deletions

diff --git a/drivers/mtd/chips/cfi_cmdset_0002.c b/drivers/mtd/chips/cfi_cmdset_0002.c
index f4da7bd552e9..537c8b097a9c 100644
--- a/drivers/mtd/chips/cfi_cmdset_0002.c
+++ b/drivers/mtd/chips/cfi_cmdset_0002.c
@@ -61,7 +61,9 @@
 
 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 *);
+#if !FORCE_WORD_WRITE
 static int cfi_amdstd_write_buffers(struct mtd_info *, loff_t, size_t, size_t *, const u_char *);
+#endif
 static int cfi_amdstd_erase_chip(struct mtd_info *, struct erase_info *);
 static int cfi_amdstd_erase_varsize(struct mtd_info *, struct erase_info *);
 static void cfi_amdstd_sync (struct mtd_info *);
@@ -256,6 +258,7 @@ static void fixup_amd_bootblock(struct mtd_info *mtd)
 }
 #endif
 
+#if !FORCE_WORD_WRITE
 static void fixup_use_write_buffers(struct mtd_info *mtd)
 {
 	struct map_info *map = mtd->priv;
@@ -265,6 +268,7 @@ static void fixup_use_write_buffers(struct mtd_info *mtd)
 		mtd->_write = cfi_amdstd_write_buffers;
 	}
 }
+#endif /* !FORCE_WORD_WRITE */
 
 /* Atmel chips don't use the same PRI format as AMD chips */
 static void fixup_convert_atmel_pri(struct mtd_info *mtd)
@@ -1637,11 +1641,11 @@ static int cfi_amdstd_lock_user_prot_reg(struct mtd_info *mtd, loff_t from,
 				   do_otp_lock, 1);
 }
 
-static int __xipram do_write_oneword(struct map_info *map, struct flchip *chip,
-				     unsigned long adr, map_word datum,
-				     int mode)
+static int __xipram do_write_oneword_once(struct map_info *map,
+					  struct flchip *chip,
+					  unsigned long adr, map_word datum,
+					  int mode, struct cfi_private *cfi)
 {
-	struct cfi_private *cfi = map->fldrv_priv;
 	unsigned long timeo = jiffies + HZ;
 	/*
 	 * We use a 1ms + 1 jiffies generic timeout for writes (most devices
@@ -1654,42 +1658,7 @@ static int __xipram do_write_oneword(struct map_info *map, struct flchip *chip,
 	 */
 	unsigned long uWriteTimeout = (HZ / 1000) + 1;
 	int ret = 0;
-	map_word oldd;
-	int retry_cnt = 0;
-
-	adr += chip->start;
-
-	mutex_lock(&chip->mutex);
-	ret = get_chip(map, chip, adr, mode);
-	if (ret) {
-		mutex_unlock(&chip->mutex);
-		return ret;
-	}
-
-	pr_debug("MTD %s(): WRITE 0x%.8lx(0x%.8lx)\n",
-		 __func__, adr, datum.x[0]);
-
-	if (mode == FL_OTP_WRITE)
-		otp_enter(map, chip, adr, map_bankwidth(map));
-
-	/*
-	 * Check for a NOP for the case when the datum to write is already
-	 * present - it saves time and works around buggy chips that corrupt
-	 * data at other locations when 0xff is written to a location that
-	 * already contains 0xff.
-	 */
-	oldd = map_read(map, adr);
-	if (map_word_equal(map, oldd, datum)) {
-		pr_debug("MTD %s(): NOP\n",
-		       __func__);
-		goto op_done;
-	}
 
-	XIP_INVAL_CACHED_RANGE(map, adr, map_bankwidth(map));
-	ENABLE_VPP(map);
-	xip_disable(map, chip, adr);
-
- retry:
 	cfi_send_gen_cmd(0xAA, cfi->addr_unlock1, chip->start, map, cfi, cfi->device_type, NULL);
 	cfi_send_gen_cmd(0x55, cfi->addr_unlock2, chip->start, map, cfi, cfi->device_type, NULL);
 	cfi_send_gen_cmd(0xA0, cfi->addr_unlock1, chip->start, map, cfi, cfi->device_type, NULL);
@@ -1717,40 +1686,125 @@ static int __xipram do_write_oneword(struct map_info *map, struct flchip *chip,
 			continue;
 		}
 
+		/*
+		 * We check "time_after" and "!chip_good" before checking
+		 * "chip_good" to avoid the failure due to scheduling.
+		 */
 		if (time_after(jiffies, timeo) &&
-		    !chip_ready(map, chip, adr)) {
+		    !chip_good(map, chip, adr, datum)) {
 			xip_enable(map, chip, adr);
 			printk(KERN_WARNING "MTD %s(): software timeout\n", __func__);
 			xip_disable(map, chip, adr);
+			ret = -EIO;
 			break;
 		}
 
-		if (chip_ready(map, chip, adr))
+		if (chip_good(map, chip, adr, datum))
 			break;
 
 		/* Latency issues. Drop the lock, wait a while and retry */
 		UDELAY(map, chip, adr, 1);
 	}
-	/* Did we succeed? */
-	if (!chip_good(map, chip, adr, datum)) {
-		/* reset on all failures. */
-		cfi_check_err_status(map, chip, adr);
-		map_write(map, CMD(0xF0), chip->start);
-		/* FIXME - should have reset delay before continuing */
 
-		if (++retry_cnt <= MAX_RETRIES)
-			goto retry;
+	return ret;
+}
 
-		ret = -EIO;
+static int __xipram do_write_oneword_start(struct map_info *map,
+					   struct flchip *chip,
+					   unsigned long adr, int mode)
+{
+	int ret = 0;
+
+	mutex_lock(&chip->mutex);
+
+	ret = get_chip(map, chip, adr, mode);
+	if (ret) {
+		mutex_unlock(&chip->mutex);
+		return ret;
 	}
-	xip_enable(map, chip, adr);
- op_done:
+
+	if (mode == FL_OTP_WRITE)
+		otp_enter(map, chip, adr, map_bankwidth(map));
+
+	return ret;
+}
+
+static void __xipram do_write_oneword_done(struct map_info *map,
+					   struct flchip *chip,
+					   unsigned long adr, int mode)
+{
 	if (mode == FL_OTP_WRITE)
 		otp_exit(map, chip, adr, map_bankwidth(map));
+
 	chip->state = FL_READY;
 	DISABLE_VPP(map);
 	put_chip(map, chip, adr);
+
 	mutex_unlock(&chip->mutex);
+}
+
+static int __xipram do_write_oneword_retry(struct map_info *map,
+					   struct flchip *chip,
+					   unsigned long adr, map_word datum,
+					   int mode)
+{
+	struct cfi_private *cfi = map->fldrv_priv;
+	int ret = 0;
+	map_word oldd;
+	int retry_cnt = 0;
+
+	/*
+	 * Check for a NOP for the case when the datum to write is already
+	 * present - it saves time and works around buggy chips that corrupt
+	 * data at other locations when 0xff is written to a location that
+	 * already contains 0xff.
+	 */
+	oldd = map_read(map, adr);
+	if (map_word_equal(map, oldd, datum)) {
+		pr_debug("MTD %s(): NOP\n", __func__);
+		return ret;
+	}
+
+	XIP_INVAL_CACHED_RANGE(map, adr, map_bankwidth(map));
+	ENABLE_VPP(map);
+	xip_disable(map, chip, adr);
+
+ retry:
+	ret = do_write_oneword_once(map, chip, adr, datum, mode, cfi);
+	if (ret) {
+		/* reset on all failures. */
+		cfi_check_err_status(map, chip, adr);
+		map_write(map, CMD(0xF0), chip->start);
+		/* FIXME - should have reset delay before continuing */
+
+		if (++retry_cnt <= MAX_RETRIES) {
+			ret = 0;
+			goto retry;
+		}
+	}
+	xip_enable(map, chip, adr);
+
+	return ret;
+}
+
+static int __xipram do_write_oneword(struct map_info *map, struct flchip *chip,
+				     unsigned long adr, map_word datum,
+				     int mode)
+{
+	int ret = 0;
+
+	adr += chip->start;
+
+	pr_debug("MTD %s(): WRITE 0x%.8lx(0x%.8lx)\n", __func__, adr,
+		 datum.x[0]);
+
+	ret = do_write_oneword_start(map, chip, adr, mode);
+	if (ret)
+		return ret;
+
+	ret = do_write_oneword_retry(map, chip, adr, datum, mode);
+
+	do_write_oneword_done(map, chip, adr, mode);
 
 	return ret;
 }
@@ -1879,6 +1933,78 @@ static int cfi_amdstd_write_words(struct mtd_info *mtd, loff_t to, size_t len,
 	return 0;
 }
 
+#if !FORCE_WORD_WRITE
+static int __xipram do_write_buffer_wait(struct map_info *map,
+					 struct flchip *chip, unsigned long adr,
+					 map_word datum)
+{
+	unsigned long timeo;
+	unsigned long u_write_timeout;
+	int ret = 0;
+
+	/*
+	 * Timeout is calculated according to CFI data, if available.
+	 * See more comments in cfi_cmdset_0002().
+	 */
+	u_write_timeout = usecs_to_jiffies(chip->buffer_write_time_max);
+	timeo = jiffies + u_write_timeout;
+
+	for (;;) {
+		if (chip->state != FL_WRITING) {
+			/* Someone's suspended the write. Sleep */
+			DECLARE_WAITQUEUE(wait, current);
+
+			set_current_state(TASK_UNINTERRUPTIBLE);
+			add_wait_queue(&chip->wq, &wait);
+			mutex_unlock(&chip->mutex);
+			schedule();
+			remove_wait_queue(&chip->wq, &wait);
+			timeo = jiffies + (HZ / 2); /* FIXME */
+			mutex_lock(&chip->mutex);
+			continue;
+		}
+
+		/*
+		 * We check "time_after" and "!chip_good" before checking
+		 * "chip_good" to avoid the failure due to scheduling.
+		 */
+		if (time_after(jiffies, timeo) &&
+		    !chip_good(map, chip, adr, datum)) {
+			ret = -EIO;
+			break;
+		}
+
+		if (chip_good(map, chip, adr, datum))
+			break;
+
+		/* Latency issues. Drop the lock, wait a while and retry */
+		UDELAY(map, chip, adr, 1);
+	}
+
+	return ret;
+}
+
+static void __xipram do_write_buffer_reset(struct map_info *map,
+					   struct flchip *chip,
+					   struct cfi_private *cfi)
+{
+	/*
+	 * Recovery from write-buffer programming failures requires
+	 * the write-to-buffer-reset sequence.  Since the last part
+	 * of the sequence also works as a normal reset, we can run
+	 * the same commands regardless of why we are here.
+	 * See e.g.
+	 * http://www.spansion.com/Support/Application%20Notes/MirrorBit_Write_Buffer_Prog_Page_Buffer_Read_AN.pdf
+	 */
+	cfi_send_gen_cmd(0xAA, cfi->addr_unlock1, chip->start, map, cfi,
+			 cfi->device_type, NULL);
+	cfi_send_gen_cmd(0x55, cfi->addr_unlock2, chip->start, map, cfi,
+			 cfi->device_type, NULL);
+	cfi_send_gen_cmd(0xF0, cfi->addr_unlock1, chip->start, map, cfi,
+			 cfi->device_type, NULL);
+
+	/* FIXME - should have reset delay before continuing */
+}
 
 /*
  * FIXME: interleaved mode not tested, and probably not supported!
@@ -1888,13 +2014,6 @@ static int __xipram do_write_buffer(struct map_info *map, struct flchip *chip,
 				    int len)
 {
 	struct cfi_private *cfi = map->fldrv_priv;
-	unsigned long timeo = jiffies + HZ;
-	/*
-	 * Timeout is calculated according to CFI data, if available.
-	 * See more comments in cfi_cmdset_0002().
-	 */
-	unsigned long uWriteTimeout =
-				usecs_to_jiffies(chip->buffer_write_time_max);
 	int ret = -EIO;
 	unsigned long cmd_adr;
 	int z, words;
@@ -1951,63 +2070,16 @@ static int __xipram do_write_buffer(struct map_info *map, struct flchip *chip,
 				adr, map_bankwidth(map),
 				chip->word_write_time);
 
-	timeo = jiffies + uWriteTimeout;
-
-	for (;;) {
-		if (chip->state != FL_WRITING) {
-			/* Someone's suspended the write. Sleep */
-			DECLARE_WAITQUEUE(wait, current);
-
-			set_current_state(TASK_UNINTERRUPTIBLE);
-			add_wait_queue(&chip->wq, &wait);
-			mutex_unlock(&chip->mutex);
-			schedule();
-			remove_wait_queue(&chip->wq, &wait);
-			timeo = jiffies + (HZ / 2); /* FIXME */
-			mutex_lock(&chip->mutex);
-			continue;
-		}
-
-		/*
-		 * We check "time_after" and "!chip_good" before checking "chip_good" to avoid
-		 * the failure due to scheduling.
-		 */
-		if (time_after(jiffies, timeo) &&
-		    !chip_good(map, chip, adr, datum))
-			break;
-
-		if (chip_good(map, chip, adr, datum)) {
-			xip_enable(map, chip, adr);
-			goto op_done;
-		}
-
-		/* Latency issues. Drop the lock, wait a while and retry */
-		UDELAY(map, chip, adr, 1);
+	ret = do_write_buffer_wait(map, chip, adr, datum);
+	if (ret) {
+		cfi_check_err_status(map, chip, adr);
+		do_write_buffer_reset(map, chip, cfi);
+		pr_err("MTD %s(): software timeout, address:0x%.8lx.\n",
+		       __func__, adr);
 	}
 
-	/*
-	 * Recovery from write-buffer programming failures requires
-	 * the write-to-buffer-reset sequence.  Since the last part
-	 * of the sequence also works as a normal reset, we can run
-	 * the same commands regardless of why we are here.
-	 * See e.g.
-	 * http://www.spansion.com/Support/Application%20Notes/MirrorBit_Write_Buffer_Prog_Page_Buffer_Read_AN.pdf
-	 */
-	cfi_check_err_status(map, chip, adr);
-	cfi_send_gen_cmd(0xAA, cfi->addr_unlock1, chip->start, map, cfi,
-			 cfi->device_type, NULL);
-	cfi_send_gen_cmd(0x55, cfi->addr_unlock2, chip->start, map, cfi,
-			 cfi->device_type, NULL);
-	cfi_send_gen_cmd(0xF0, cfi->addr_unlock1, chip->start, map, cfi,
-			 cfi->device_type, NULL);
 	xip_enable(map, chip, adr);
-	/* FIXME - should have reset delay before continuing */
-
-	printk(KERN_WARNING "MTD %s(): software timeout, address:0x%.8lx.\n",
-	       __func__, adr);
 
-	ret = -EIO;
- op_done:
 	chip->state = FL_READY;
 	DISABLE_VPP(map);
 	put_chip(map, chip, adr);
@@ -2091,6 +2163,7 @@ static int cfi_amdstd_write_buffers(struct mtd_info *mtd, loff_t to, size_t len,
 
 	return 0;
 }
+#endif /* !FORCE_WORD_WRITE */
 
 /*
  * Wait for the flash chip to become ready to write data
diff --git a/drivers/mtd/chips/gen_probe.c b/drivers/mtd/chips/gen_probe.c
index 839ed40625d6..e5bd3c2bc3b2 100644
--- a/drivers/mtd/chips/gen_probe.c
+++ b/drivers/mtd/chips/gen_probe.c
@@ -20,7 +20,7 @@ static int genprobe_new_chip(struct map_info *map, struct chip_probe *cp,
 
 struct mtd_info *mtd_do_chip_probe(struct map_info *map, struct chip_probe *cp)
 {
-	struct mtd_info *mtd = NULL;
+	struct mtd_info *mtd;
 	struct cfi_private *cfi;
 
 	/* First probe the map to see if we have CFI stuff there. */