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authorDaniel Mack <daniel@zonque.org>2023-10-18 12:46:13 +0300
committerWolfram Sang <wsa@kernel.org>2023-10-28 15:47:49 +0300
commit53801d2e762a611d972e91d151df56c3412ca5cf (patch)
tree31d84bdd47d81cd1ea2cac81dd01ef0a614960dd /drivers/i2c
parent702c0dd7bcf169c44cb4a67447532861877c2744 (diff)
downloadlinux-53801d2e762a611d972e91d151df56c3412ca5cf.tar.xz
i2c: core: fix lockdep warning for sparsely nested adapter chain
When adapters are chained in a sparse manner (with intermediate MFD devices, for instance) the code currently fails to use the correct subclass for the adapter's bus_lock which leads to false-positive lockdep warnings. Fix this by walking the entire pedigree of the device and count all adapters along the way instead of just checking the immediate parent. Signed-off-by: Daniel Mack <daniel@zonque.org> Signed-off-by: Wolfram Sang <wsa@kernel.org>
Diffstat (limited to 'drivers/i2c')
-rw-r--r--drivers/i2c/i2c-core-base.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index 7f30bcceebae..eac90a3cf61a 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -1194,9 +1194,11 @@ static void i2c_adapter_dev_release(struct device *dev)
unsigned int i2c_adapter_depth(struct i2c_adapter *adapter)
{
unsigned int depth = 0;
+ struct device *parent;
- while ((adapter = i2c_parent_is_i2c_adapter(adapter)))
- depth++;
+ for (parent = adapter->dev.parent; parent; parent = parent->parent)
+ if (parent->type == &i2c_adapter_type)
+ depth++;
WARN_ONCE(depth >= MAX_LOCKDEP_SUBCLASSES,
"adapter depth exceeds lockdep subclass limit\n");