[PATCH 34/58] mtd: rawnand: omap2: retain open-handle state on removal

[James Hilliard]

Keep chip metadata and controller storage alive until the final MTD
reference is released. Unregister and disconnect each published chip
before releasing the resources used by its hardware operations.

Preserve the shared GPMC lock and separately retain each device's state.

Signed-off-by: James Hilliard <james.hilliard1 at gmail.com>
---
 drivers/mtd/nand/raw/omap2.c | 45 ++++++++++++++++++++++++++++++++++++--------
 1 file changed, 37 insertions(+), 8 deletions(-)

diff --git a/drivers/mtd/nand/raw/omap2.c b/drivers/mtd/nand/raw/omap2.c
index 4909e62dc11e..9949d4d53299 100644
--- a/drivers/mtd/nand/raw/omap2.c
+++ b/drivers/mtd/nand/raw/omap2.c
@@ -142,6 +142,7 @@ static u_char bch8_vector[] = {0xf3, 0xdb, 0x14, 0x16, 0x8b, 0xd2, 0xbe, 0xcc,
 static u_char bch4_vector[] = {0x00, 0x6b, 0x31, 0xdd, 0x41, 0xbc, 0x10};
 
 struct omap_nand_info {
+	struct kref			refcnt;
 	struct nand_chip		nand;
 	struct platform_device		*pdev;
 
@@ -2208,6 +2209,24 @@ static const struct nand_controller_ops omap_nand_controller_ops = {
 static struct nand_controller omap_gpmc_controller;
 static bool omap_gpmc_controller_initialized;
 
+static void omap_nand_info_release(struct kref *ref)
+{
+	kfree(container_of(ref, struct omap_nand_info, refcnt));
+}
+
+static void omap_nand_info_put(void *data)
+{
+	struct omap_nand_info *info = data;
+
+	kref_put(&info->refcnt, omap_nand_info_release);
+}
+
+static void omap_nand_release(struct nand_chip *chip)
+{
+	rawnand_sw_bch_cleanup(chip);
+	omap_nand_info_put(mtd_to_omap(nand_to_mtd(chip)));
+}
+
 static int omap_nand_probe(struct platform_device *pdev)
 {
 	struct omap_nand_info		*info;
@@ -2218,10 +2237,13 @@ static int omap_nand_probe(struct platform_device *pdev)
 	struct device			*dev = &pdev->dev;
 	void __iomem *vaddr;
 
-	info = devm_kzalloc(&pdev->dev, sizeof(struct omap_nand_info),
-				GFP_KERNEL);
+	info = kzalloc_obj(*info);
 	if (!info)
 		return -ENOMEM;
+	kref_init(&info->refcnt);
+	err = devm_add_action_or_reset(dev, omap_nand_info_put, info);
+	if (err)
+		return err;
 
 	info->pdev = pdev;
 
@@ -2282,9 +2304,16 @@ static int omap_nand_probe(struct platform_device *pdev)
 	if (err)
 		goto return_error;
 
-	err = mtd_device_register(mtd, NULL, 0);
+	err = nand_set_release(nand_chip, omap_nand_release);
 	if (err)
 		goto cleanup_nand;
+	kref_get(&info->refcnt);
+	err = mtd_device_register(mtd, NULL, 0);
+	if (err) {
+		nand_disconnect(nand_chip);
+		mtd_put_master(mtd);
+		goto release_dma;
+	}
 
 	platform_set_drvdata(pdev, mtd);
 
@@ -2294,11 +2323,11 @@ static int omap_nand_probe(struct platform_device *pdev)
 	nand_cleanup(nand_chip);
 
 return_error:
+	rawnand_sw_bch_cleanup(nand_chip);
+release_dma:
 	if (!IS_ERR_OR_NULL(info->dma))
 		dma_release_channel(info->dma);
 
-	rawnand_sw_bch_cleanup(nand_chip);
-
 	return err;
 }
 
@@ -2308,12 +2337,12 @@ static void omap_nand_remove(struct platform_device *pdev)
 	struct nand_chip *nand_chip = mtd_to_nand(mtd);
 	struct omap_nand_info *info = mtd_to_omap(mtd);
 
-	rawnand_sw_bch_cleanup(nand_chip);
+	WARN_ON(mtd_device_unregister(mtd));
+	nand_disconnect(nand_chip);
 
 	if (info->dma)
 		dma_release_channel(info->dma);
-	WARN_ON(mtd_device_unregister(mtd));
-	nand_cleanup(nand_chip);
+	mtd_put_master(mtd);
 }
 
 static const struct of_device_id omap_nand_ids[] = {

-- 
2.53.0