Merge tag 'regmap-v6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap

Pull regmap updates from Mark Brown:
 "The main change here is a fix for an issue where we were letting the
  selector for windowed register ranges get out of sync with the
  hardware during a cache sync plus associated KUnit tests. This was
  reported just at the end of the release cycle and only in -next for a
  day prior to the merge window so it seemed better to hold off for now,
  the bug had been present for more than a decade so wasn't causing too
  many practical problems hopefully.

  There's also a fix for error handling in the debugfs output from
  Christope Jaillet"

* tag 'regmap-v6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap:
  regmap: Ensure range selector registers are updated after cache sync
  regmap: kunit: Add test for cache sync interaction with ranges
  regmap: kunit: Fix marking of the range window as volatile
  regmap: debugfs: Fix a erroneous check after snprintf()

1 files changed, 30 insertions, 0 deletions

diff --git a/drivers/base/regmap/regcache.c b/drivers/base/regmap/regcache.c
index c5d151e9c481..92592f944a3d 100644
--- a/drivers/base/regmap/regcache.c
+++ b/drivers/base/regmap/regcache.c
@@ -334,6 +334,11 @@ static int regcache_default_sync(struct regmap *map, unsigned int min,
 	return 0;
 }
 
+static int rbtree_all(const void *key, const struct rb_node *node)
+{
+	return 0;
+}
+
 /**
  * regcache_sync - Sync the register cache with the hardware.
  *
@@ -351,6 +356,7 @@ int regcache_sync(struct regmap *map)
 	unsigned int i;
 	const char *name;
 	bool bypass;
+	struct rb_node *node;
 
 	if (WARN_ON(map->cache_type == REGCACHE_NONE))
 		return -EINVAL;
@@ -392,6 +398,30 @@ out:
 	/* Restore the bypass state */
 	map->cache_bypass = bypass;
 	map->no_sync_defaults = false;
+
+	/*
+	 * If we did any paging with cache bypassed and a cached
+	 * paging register then the register and cache state might
+	 * have gone out of sync, force writes of all the paging
+	 * registers.
+	 */
+	rb_for_each(node, 0, &map->range_tree, rbtree_all) {
+		struct regmap_range_node *this =
+			rb_entry(node, struct regmap_range_node, node);
+
+		/* If there's nothing in the cache there's nothing to sync */
+		ret = regcache_read(map, this->selector_reg, &i);
+		if (ret != 0)
+			continue;
+
+		ret = _regmap_write(map, this->selector_reg, i);
+		if (ret != 0) {
+			dev_err(map->dev, "Failed to write %x = %x: %d\n",
+				this->selector_reg, i, ret);
+			break;
+		}
+	}
+
 	map->unlock(map->lock_arg);
 
 	regmap_async_complete(map);