When in the list_for_each_entry iteration, reload of p->state->settings with a local setting from old_state will makes the list iteration in a infinite loop. The typical issue happened, it will frequently have printk message like: "not freeing pin xx (xxx) as part of deactivating group xxx - it is already used for some other setting". This is a compiler-dependent problem, one instance was got using Clang version 10.0 plus arm64 architecture with linux version 4.19.
Fixes: 6e5e959dde0d ("pinctrl: API changes to support multiple states per device") Signed-off-by: Maria Yu quic_aiquny@quicinc.com Cc: stable@vger.kernel.org --- drivers/pinctrl/core.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c index 1fa89be29b8f..f2977eb65522 100644 --- a/drivers/pinctrl/core.c +++ b/drivers/pinctrl/core.c @@ -1262,17 +1262,17 @@ static void pinctrl_link_add(struct pinctrl_dev *pctldev, static int pinctrl_commit_state(struct pinctrl *p, struct pinctrl_state *state) { struct pinctrl_setting *setting, *setting2; - struct pinctrl_state *old_state = p->state; + struct pinctrl_state *old_state = READ_ONCE(p->state); int ret;
- if (p->state) { + if (old_state) { /* * For each pinmux setting in the old state, forget SW's record * of mux owner for that pingroup. Any pingroups which are * still owned by the new state will be re-acquired by the call * to pinmux_enable_setting() in the loop below. */ - list_for_each_entry(setting, &p->state->settings, node) { + list_for_each_entry(setting, &old_state->settings, node) { if (setting->type != PIN_MAP_TYPE_MUX_GROUP) continue; pinmux_disable_setting(setting);
base-commit: 9bacdd8996c77c42ca004440be610692275ff9d0