Merge tag 'regmap-fix-v6.17-merge-window' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap

Pull regmap fixes from Mark Brown:
 "These patches fix a lockdep issue Russell King reported with nested
  regmap-irqs (unusual since regmap is generally for devices on slow
  buses so devices don't get nested), plus add a missing mutex free
  which I noticed while implementing a fix for that issue"

* tag 'regmap-fix-v6.17-merge-window' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap:
  regmap: irq: Avoid lockdep warnings with nested regmap-irq chips
  regmap: irq: Free the regmap-irq mutex

1 files changed, 21 insertions, 9 deletions

diff --git a/drivers/base/regmap/regmap-irq.c b/drivers/base/regmap/regmap-irq.c
index d1585f073776..6112d942499b 100644
--- a/drivers/base/regmap/regmap-irq.c
+++ b/drivers/base/regmap/regmap-irq.c
@@ -21,6 +21,7 @@
 
 struct regmap_irq_chip_data {
 	struct mutex lock;
+	struct lock_class_key lock_key;
 	struct irq_chip irq_chip;
 
 	struct regmap *map;
@@ -801,7 +802,13 @@ int regmap_add_irq_chip_fwnode(struct fwnode_handle *fwnode,
 			goto err_alloc;
 	}
 
-	mutex_init(&d->lock);
+	/*
+	 * If one regmap-irq is the parent of another then we'll try
+	 * to lock the child with the parent locked, use an explicit
+	 * lock_key so lockdep can figure out what's going on.
+	 */
+	lockdep_register_key(&d->lock_key);
+	mutex_init_with_key(&d->lock, &d->lock_key);
 
 	for (i = 0; i < chip->num_irqs; i++)
 		d->mask_buf_def[chip->irqs[i].reg_offset / map->reg_stride]
@@ -816,7 +823,7 @@ int regmap_add_irq_chip_fwnode(struct fwnode_handle *fwnode,
 						     d->mask_buf[i],
 						     chip->irq_drv_data);
 			if (ret)
-				goto err_alloc;
+				goto err_mutex;
 		}
 
 		if (chip->mask_base && !chip->handle_mask_sync) {
@@ -827,7 +834,7 @@ int regmap_add_irq_chip_fwnode(struct fwnode_handle *fwnode,
 			if (ret) {
 				dev_err(map->dev, "Failed to set masks in 0x%x: %d\n",
 					reg, ret);
-				goto err_alloc;
+				goto err_mutex;
 			}
 		}
 
@@ -838,7 +845,7 @@ int regmap_add_irq_chip_fwnode(struct fwnode_handle *fwnode,
 			if (ret) {
 				dev_err(map->dev, "Failed to set masks in 0x%x: %d\n",
 					reg, ret);
-				goto err_alloc;
+				goto err_mutex;
 			}
 		}
 
@@ -855,7 +862,7 @@ int regmap_add_irq_chip_fwnode(struct fwnode_handle *fwnode,
 			if (ret != 0) {
 				dev_err(map->dev, "Failed to read IRQ status: %d\n",
 					ret);
-				goto err_alloc;
+				goto err_mutex;
 			}
 		}
 
@@ -879,7 +886,7 @@ int regmap_add_irq_chip_fwnode(struct fwnode_handle *fwnode,
 			if (ret != 0) {
 				dev_err(map->dev, "Failed to ack 0x%x: %d\n",
 					reg, ret);
-				goto err_alloc;
+				goto err_mutex;
 			}
 		}
 	}
@@ -901,7 +908,7 @@ int regmap_add_irq_chip_fwnode(struct fwnode_handle *fwnode,
 			if (ret != 0) {
 				dev_err(map->dev, "Failed to set masks in 0x%x: %d\n",
 					reg, ret);
-				goto err_alloc;
+				goto err_mutex;
 			}
 		}
 	}
@@ -910,7 +917,7 @@ int regmap_add_irq_chip_fwnode(struct fwnode_handle *fwnode,
 	if (chip->status_is_level) {
 		ret = read_irq_data(d);
 		if (ret < 0)
-			goto err_alloc;
+			goto err_mutex;
 
 		memcpy(d->prev_status_buf, d->status_buf,
 		       array_size(d->chip->num_regs, sizeof(d->prev_status_buf[0])));
@@ -918,7 +925,7 @@ int regmap_add_irq_chip_fwnode(struct fwnode_handle *fwnode,
 
 	ret = regmap_irq_create_domain(fwnode, irq_base, chip, d);
 	if (ret)
-		goto err_alloc;
+		goto err_mutex;
 
 	ret = request_threaded_irq(irq, NULL, regmap_irq_thread,
 				   irq_flags | IRQF_ONESHOT,
@@ -935,6 +942,9 @@ int regmap_add_irq_chip_fwnode(struct fwnode_handle *fwnode,
 
 err_domain:
 	/* Should really dispose of the domain but... */
+err_mutex:
+	mutex_destroy(&d->lock);
+	lockdep_unregister_key(&d->lock_key);
 err_alloc:
 	kfree(d->type_buf);
 	kfree(d->type_buf_def);
@@ -1027,6 +1037,8 @@ void regmap_del_irq_chip(int irq, struct regmap_irq_chip_data *d)
 			kfree(d->config_buf[i]);
 		kfree(d->config_buf);
 	}
+	mutex_destroy(&d->lock);
+	lockdep_unregister_key(&d->lock_key);
 	kfree(d);
 }
 EXPORT_SYMBOL_GPL(regmap_del_irq_chip);