From 13619170303878e1dae86d9a58b039475c957fcf Mon Sep 17 00:00:00 2001 From: Rob Clark Date: Mon, 7 Aug 2023 10:11:41 -0700 Subject: [PATCH] interconnect: Teach lockdep about icc_bw_lock order Teach lockdep that icc_bw_lock is needed in code paths that could deadlock if they trigger reclaim. Signed-off-by: Rob Clark Link: https://lore.kernel.org/r/20230807171148.210181-8-robdclark@gmail.com Signed-off-by: Georgi Djakov --- drivers/interconnect/core.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/interconnect/core.c b/drivers/interconnect/core.c index e15a92a79df1..1afbc4f7c6e7 100644 --- a/drivers/interconnect/core.c +++ b/drivers/interconnect/core.c @@ -1041,13 +1041,21 @@ void icc_sync_state(struct device *dev) } } } + mutex_unlock(&icc_bw_lock); mutex_unlock(&icc_lock); } EXPORT_SYMBOL_GPL(icc_sync_state); static int __init icc_init(void) { - struct device_node *root = of_find_node_by_path("/"); + struct device_node *root; + + /* Teach lockdep about lock ordering wrt. shrinker: */ + fs_reclaim_acquire(GFP_KERNEL); + might_lock(&icc_bw_lock); + fs_reclaim_release(GFP_KERNEL); + + root = of_find_node_by_path("/"); providers_count = of_count_icc_providers(root); of_node_put(root);