[PATCH 49/58] mtd: rawnand: txx9ndfmc: retain chip state across removal

[James Hilliard]

Retain each chip and its shared controller while MTD references remain.
Unregister and disconnect before dropping driver ownership, and check
MTD registration failure without publishing partially initialized chip
slots.

Signed-off-by: James Hilliard <james.hilliard1 at gmail.com>
---
 drivers/mtd/nand/raw/txx9ndfmc.c | 42 +++++++++++++++++++++++++++++++---------
 1 file changed, 33 insertions(+), 9 deletions(-)

diff --git a/drivers/mtd/nand/raw/txx9ndfmc.c b/drivers/mtd/nand/raw/txx9ndfmc.c
index 4cc6e91dbc23..9eae5002e389 100644
--- a/drivers/mtd/nand/raw/txx9ndfmc.c
+++ b/drivers/mtd/nand/raw/txx9ndfmc.c
@@ -276,17 +276,33 @@ static const struct nand_controller_ops txx9ndfmc_controller_ops = {
 	.attach_chip = txx9ndfmc_attach_chip,
 };
 
+static void txx9ndfmc_chip_release(struct nand_chip *chip)
+{
+	struct txx9ndfmc_priv *priv = nand_get_controller_data(chip);
+
+	kfree(priv->mtdname);
+	kfree(priv);
+}
+
+static void txx9ndfmc_release(struct nand_controller *controller)
+{
+	kfree(container_of(controller, struct txx9ndfmc_drvdata, controller));
+}
+
 static int txx9ndfmc_probe(struct platform_device *dev)
 {
 	struct txx9ndfmc_platform_data *plat = dev_get_platdata(&dev->dev);
 	int hold, spw;
-	int i;
+	int i, ret;
 	struct txx9ndfmc_drvdata *drvdata;
 	unsigned long gbusclk = plat->gbus_clock;
 
-	drvdata = devm_kzalloc(&dev->dev, sizeof(*drvdata), GFP_KERNEL);
+	drvdata = kzalloc_obj(*drvdata);
 	if (!drvdata)
 		return -ENOMEM;
+	ret = devm_nand_controller_init(&dev->dev, &drvdata->controller, txx9ndfmc_release);
+	if (ret)
+		return ret;
 	drvdata->base = devm_platform_ioremap_resource(dev, 0);
 	if (IS_ERR(drvdata->base))
 		return PTR_ERR(drvdata->base);
@@ -306,7 +322,6 @@ static int txx9ndfmc_probe(struct platform_device *dev)
 	dev_info(&dev->dev, "CLK:%ldMHz HOLD:%d SPW:%d\n",
 		 (gbusclk + 500000) / 1000000, hold, spw);
 
-	nand_controller_init(&drvdata->controller);
 	drvdata->controller.ops = &txx9ndfmc_controller_ops;
 
 	platform_set_drvdata(dev, drvdata);
@@ -361,7 +376,18 @@ static int txx9ndfmc_probe(struct platform_device *dev)
 		}
 		mtd->name = txx9_priv->mtdname;
 
-		mtd_device_register(mtd, NULL, 0);
+		ret = nand_set_release(chip, txx9ndfmc_chip_release);
+		if (ret) {
+			nand_cleanup(chip);
+			txx9ndfmc_chip_release(chip);
+			continue;
+		}
+		ret = mtd_device_register(mtd, NULL, 0);
+		if (ret) {
+			nand_disconnect(chip);
+			mtd_put_master(mtd);
+			continue;
+		}
 		drvdata->mtds[i] = mtd;
 	}
 
@@ -376,18 +402,16 @@ static void txx9ndfmc_remove(struct platform_device *dev)
 	for (i = 0; i < MAX_TXX9NDFMC_DEV; i++) {
 		struct mtd_info *mtd = drvdata->mtds[i];
 		struct nand_chip *chip;
-		struct txx9ndfmc_priv *txx9_priv;
 
 		if (!mtd)
 			continue;
 		chip = mtd_to_nand(mtd);
-		txx9_priv = nand_get_controller_data(chip);
 
 		ret = mtd_device_unregister(nand_to_mtd(chip));
 		WARN_ON(ret);
-		nand_cleanup(chip);
-		kfree(txx9_priv->mtdname);
-		kfree(txx9_priv);
+		nand_disconnect(chip);
+		drvdata->mtds[i] = NULL;
+		mtd_put_master(mtd);
 	}
 }
 

-- 
2.53.0