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From:   Sean Nyekjaer <sean@geanix.com>
To:     Boris Brezillon <boris.brezillon@collabora.com>
Cc:     Sean Nyekjaer <sean@geanix.com>,
        Miquel Raynal <miquel.raynal@bootlin.com>,
        Richard Weinberger <richard@nod.at>,
        Vignesh Raghavendra <vigneshr@ti.com>,
        Boris Brezillon <bbrezillon@kernel.org>,
        linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: [RFC PATCH 2/2] mtd: rawnand: remove suspended check
Date:   Fri,  8 Oct 2021 16:38:25 +0200
Message-Id: <20211008143825.3717116-2-sean@geanix.com>
In-Reply-To: <20211008141524.20ca8219@collabora.com>
References: <20211008143825.3717116-1-sean@geanix.com>
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Rawnand access is protected in upper mtd layer when mtd devices are
suspended. So remove this obsolute check/lock

Fixes: 013e6292aaf5 ("mtd: rawnand: Simplify the locking")
Signed-off-by: Sean Nyekjaer <sean@geanix.com>
---

Hmm what to do in nand_sync()? Fine as is?

 drivers/mtd/nand/raw/nand_base.c | 50 ++++++++------------------------
 include/linux/mtd/rawnand.h      |  5 +---
 2 files changed, 13 insertions(+), 42 deletions(-)

diff --git a/drivers/mtd/nand/raw/nand_base.c b/drivers/mtd/nand/raw/nand_base.c
index 3d6c6e880520..f1f85866c87a 100644
--- a/drivers/mtd/nand/raw/nand_base.c
+++ b/drivers/mtd/nand/raw/nand_base.c
@@ -332,19 +332,11 @@ static int nand_isbad_bbm(struct nand_chip *chip, loff_t ofs)
  * @chip: NAND chip structure
  *
  * Lock the device and its controller for exclusive access
- *
- * Return: -EBUSY if the chip has been suspended, 0 otherwise
  */
-static int nand_get_device(struct nand_chip *chip)
+static void nand_get_device(struct nand_chip *chip)
 {
 	mutex_lock(&chip->lock);
-	if (chip->suspended) {
-		mutex_unlock(&chip->lock);
-		return -EBUSY;
-	}
 	mutex_lock(&chip->controller->lock);
-
-	return 0;
 }
 
 /**
@@ -573,10 +565,7 @@ static int nand_block_markbad_lowlevel(struct nand_chip *chip, loff_t ofs)
 		nand_erase_nand(chip, &einfo, 0);
 
 		/* Write bad block marker to OOB */
-		ret = nand_get_device(chip);
-		if (ret)
-			return ret;
-
+		nand_get_device(chip);
 		ret = nand_markbad_bbm(chip, ofs);
 		nand_release_device(chip);
 	}
@@ -3756,9 +3745,7 @@ static int nand_read_oob(struct mtd_info *mtd, loff_t from,
 	    ops->mode != MTD_OPS_RAW)
 		return -ENOTSUPP;
 
-	ret = nand_get_device(chip);
-	if (ret)
-		return ret;
+	nand_get_device(chip);
 
 	if (!ops->datbuf)
 		ret = nand_do_read_oob(chip, from, ops);
@@ -4349,9 +4336,7 @@ static int nand_write_oob(struct mtd_info *mtd, loff_t to,
 
 	ops->retlen = 0;
 
-	ret = nand_get_device(chip);
-	if (ret)
-		return ret;
+	nand_get_device(chip);
 
 	switch (ops->mode) {
 	case MTD_OPS_PLACE_OOB:
@@ -4410,10 +4395,8 @@ int nand_erase_nand(struct nand_chip *chip, struct erase_info *instr,
 	if (nand_region_is_secured(chip, instr->addr, instr->len))
 		return -EIO;
 
-	/* Grab the lock and see if the device is available */
-	ret = nand_get_device(chip);
-	if (ret)
-		return ret;
+	/* Grab the lock */
+	nand_get_device(chip);
 
 	/* Shift to get first page */
 	page = (int)(instr->addr >> chip->page_shift);
@@ -4499,8 +4482,8 @@ static void nand_sync(struct mtd_info *mtd)
 
 	pr_debug("%s: called\n", __func__);
 
-	/* Grab the lock and see if the device is available */
-	WARN_ON(nand_get_device(chip));
+	/* Grab the lock */
+	nand_get_device(chip);
 	/* Release it and go back */
 	nand_release_device(chip);
 }
@@ -4517,9 +4500,7 @@ static int nand_block_isbad(struct mtd_info *mtd, loff_t offs)
 	int ret;
 
 	/* Select the NAND device */
-	ret = nand_get_device(chip);
-	if (ret)
-		return ret;
+	nand_get_device(chip);
 
 	nand_select_target(chip, chipnr);
 
@@ -4565,8 +4546,6 @@ static int nand_suspend(struct mtd_info *mtd)
 	mutex_lock(&chip->lock);
 	if (chip->ops.suspend)
 		ret = chip->ops.suspend(chip);
-	if (!ret)
-		chip->suspended = 1;
 	mutex_unlock(&chip->lock);
 
 	return ret;
@@ -4580,15 +4559,10 @@ static void nand_resume(struct mtd_info *mtd)
 {
 	struct nand_chip *chip = mtd_to_nand(mtd);
 
+
 	mutex_lock(&chip->lock);
-	if (chip->suspended) {
-		if (chip->ops.resume)
-			chip->ops.resume(chip);
-		chip->suspended = 0;
-	} else {
-		pr_err("%s called for a chip which is not in suspended state\n",
-			__func__);
-	}
+	if (chip->ops.resume)
+		chip->ops.resume(chip);
 	mutex_unlock(&chip->lock);
 }
 
diff --git a/include/linux/mtd/rawnand.h b/include/linux/mtd/rawnand.h
index b2f9dd3cbd69..1198a6548912 100644
--- a/include/linux/mtd/rawnand.h
+++ b/include/linux/mtd/rawnand.h
@@ -1237,9 +1237,7 @@ struct nand_secure_region {
  * @pagecache.page: Page number currently in the cache. -1 means no page is
  *                  currently cached
  * @buf_align: Minimum buffer alignment required by a platform
- * @lock: Lock protecting the suspended field. Also used to serialize accesses
- *        to the NAND device
- * @suspended: Set to 1 when the device is suspended, 0 when it's not
+ * @lock: Lock to serialize accesses to the NAND device
  * @cur_cs: Currently selected target. -1 means no target selected, otherwise we
  *          should always have cur_cs >= 0 && cur_cs < nanddev_ntargets().
  *          NAND Controller drivers should not modify this value, but they're
@@ -1293,7 +1291,6 @@ struct nand_chip {
 
 	/* Internals */
 	struct mutex lock;
-	unsigned int suspended : 1;
 	int cur_cs;
 	int read_retries;
 	struct nand_secure_region *secure_regions;
-- 
2.33.0