From 632d31067be2f414c57955efcf29c79290cc749b Mon Sep 17 00:00:00 2001 From: Pin-yen Lin Date: Fri, 26 Sep 2025 18:23:18 +0800 Subject: PM: sleep: Do not wait on SYNC_STATE_ONLY device links Device links with DL_FLAG_SYNC_STATE_ONLY should not affect system suspend and resume, and functions like device_reorder_to_tail() and device_link_add() don't try to reorder the consumers with that flag. However, dpm_wait_for_consumers() and dpm_wait_for_suppliers() don't check thas flag before triggering dpm_wait(), leading to potential hang during suspend/resume. This can be reproduced on MT8186 Corsola Chromebook with devicetree like: usb-a-connector { compatible = "usb-a-connector"; port { usb_a_con: endpoint { remote-endpoint = <&usb_hs>; }; }; }; usb_host { compatible = "mediatek,mt8186-xhci", "mediatek,mtk-xhci"; port { usb_hs: endpoint { remote-endpoint = <&usb_a_con>; }; }; }; In this case, the two nodes form a cycle and a SYNC_STATE_ONLY devlink between usb_host (supplier) and usb-a-connector (consumer) is created. Address this by exporting device_link_flag_is_sync_state_only() and making dpm_wait_for_consumers() and dpm_wait_for_suppliers() use it when deciding if dpm_wait() should be called. Fixes: 05ef983e0d65a ("driver core: Add device link support for SYNC_STATE_ONLY flag") Signed-off-by: Pin-yen Lin Link: https://patch.msgid.link/20250926102320.4053167-1-treapking@chromium.org [ rjw: Subject and changelog edits ] Signed-off-by: Rafael J. Wysocki --- drivers/base/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/base/core.c') diff --git a/drivers/base/core.c b/drivers/base/core.c index d22d6b23e758..a54ec6df1058 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -287,7 +287,7 @@ static bool device_is_ancestor(struct device *dev, struct device *target) #define DL_MARKER_FLAGS (DL_FLAG_INFERRED | \ DL_FLAG_CYCLE | \ DL_FLAG_MANAGED) -static inline bool device_link_flag_is_sync_state_only(u32 flags) +bool device_link_flag_is_sync_state_only(u32 flags) { return (flags & ~DL_MARKER_FLAGS) == DL_FLAG_SYNC_STATE_ONLY; } -- cgit v1.2.3