[3.16.y-ckt stable] Patch "mtd: nand: remove unused and buggy get_platform_nandchip() helper function" has been added to the 3.16.y-ckt tree

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    mtd: nand: remove unused and buggy get_platform_nandchip() helper function

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt24.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

---8<------------------------------------------------------------

>From f1b1b603033d86883b8c0cfd591d1ac93c680e5c Mon Sep 17 00:00:00 2001
From: Boris BREZILLON <boris.brezillon at free-electrons.com>
Date: Mon, 14 Dec 2015 16:13:31 +0100
Subject: mtd: nand: remove unused and buggy get_platform_nandchip() helper
 function

commit 8142b47ef33c655a34e08efd46b65732fe190675 upstream.

Nobody uses the get_platform_nandchip() helper function which is supposed
to return a pointer to a platform_nand_chip struct from an mtd_info
pointer.
Moreover, this function is buggy since the introduction of the plat_nand
layer (chip->priv is now storing a pointer to an intermediate
plat_nand_data structure allocated in plat_nand_probe(), and we have no
way to retrieve a pointer to the provided platform_nand_chip struct from
this plat_nand_data pointer).

While we are at it, remove the useless (and buggy, since it's pointing to
something stored on the stack) data->chip.priv assignment.

Signed-off-by: Boris Brezillon <boris.brezillon at free-electrons.com>
Fixes: 711fdf627ce1 ("[MTD] [NAND] platform NAND driver: add driver")
Cc: Vitaly Wool <vitalywool at gmail.com>
Signed-off-by: Brian Norris <computersforpeace at gmail.com>
[ luis: backported to 3.16: adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/mtd/nand/plat_nand.c | 1 -
 include/linux/mtd/nand.h     | 9 ---------
 2 files changed, 10 deletions(-)

diff --git a/drivers/mtd/nand/plat_nand.c b/drivers/mtd/nand/plat_nand.c
index 0b068a5c0bff..d6fe74f5f208 100644
--- a/drivers/mtd/nand/plat_nand.c
+++ b/drivers/mtd/nand/plat_nand.c
@@ -59,7 +59,6 @@ static int plat_nand_probe(struct platform_device *pdev)
 	if (IS_ERR(data->io_base))
 		return PTR_ERR(data->io_base);

-	data->chip.priv = &data;
 	data->mtd.priv = &data->chip;
 	data->mtd.owner = THIS_MODULE;
 	data->mtd.name = dev_name(&pdev->dev);
diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h
index 2b468f73f53d..6ea81247968e 100644
--- a/include/linux/mtd/nand.h
+++ b/include/linux/mtd/nand.h
@@ -882,15 +882,6 @@ struct platform_nand_data {
 	struct platform_nand_ctrl ctrl;
 };

-/* Some helpers to access the data structures */
-static inline
-struct platform_nand_chip *get_platform_nandchip(struct mtd_info *mtd)
-{
-	struct nand_chip *chip = mtd->priv;
-
-	return chip->priv;
-}
-
 /* return the supported features. */
 static inline int onfi_feature(struct nand_chip *chip)
 {