From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7B9B62F12DE; Fri, 17 Oct 2025 15:30:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760715007; cv=none; b=bAaEA34c4Jq0Hb26/nhOAliC4zdINr3RKWwWZMSApUzBQNxvLJH8q41lsztAnDic6Ni3CvXXzToRbvm+j5K3Zvjoqwab2pN5JjlkCgKoJ07PZB7txbubiu+BPDkBvDCdD7YoCYO4DZPUoSLWl8psy/2qkOiS/vwGes6nKOJuKkA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760715007; c=relaxed/simple; bh=hdD1bYoR5kKdEK9bTeQjN5oWawvtwkFpHWbYvtWjUKg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=IokPopEvBBbl+7kidt855tzZUgYxCmiU2z3ebRF7Y+x7v94lRLIIEQ5iYKEUp0FdWdVVO0iRmB6QDXWqeaVPUTaKa72Jp2MfdFEBWPaeZbsEbb66o/1K4hJi9PsNmbslca/qYr7HyCwpNqYnUbJjVLTHGHP4RzhVbWMfYWtm/+Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=DwP6fz9U; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="DwP6fz9U" Received: by smtp.kernel.org (Postfix) with ESMTPSA id F31D1C4CEE7; Fri, 17 Oct 2025 15:30:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1760715007; bh=hdD1bYoR5kKdEK9bTeQjN5oWawvtwkFpHWbYvtWjUKg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DwP6fz9UD45O2rzhXpE83TUvhji47SmPFIsPFoSlllRlzoQS3Dntca0N3Ob9SLvrw r/xHfsfm8urCzxPg5cyQ7USvo3PIcFNqOTIt9VNz1CUWaLikrbsjblOQVkpi216aMh FgJuTIJH7S5zsK8sqo6GV/qL7WgUcpVshHFFqCNQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Pin-yen Lin , "Rafael J. Wysocki" , Sasha Levin Subject: [PATCH 6.17 066/371] PM: sleep: Do not wait on SYNC_STATE_ONLY device links Date: Fri, 17 Oct 2025 16:50:41 +0200 Message-ID: <20251017145204.188960438@linuxfoundation.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20251017145201.780251198@linuxfoundation.org> References: <20251017145201.780251198@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: Pin-yen Lin [ Upstream commit 632d31067be2f414c57955efcf29c79290cc749b ] 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 Signed-off-by: Sasha Levin --- drivers/base/base.h | 1 + drivers/base/core.c | 2 +- drivers/base/power/main.c | 6 ++++-- 3 files changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/base/base.h b/drivers/base/base.h index 700aecd22fd34..86fa7fbb35489 100644 --- a/drivers/base/base.h +++ b/drivers/base/base.h @@ -248,6 +248,7 @@ void device_links_driver_cleanup(struct device *dev); void device_links_no_driver(struct device *dev); bool device_links_busy(struct device *dev); void device_links_unbind_consumers(struct device *dev); +bool device_link_flag_is_sync_state_only(u32 flags); void fw_devlink_drivers_done(void); void fw_devlink_probing_done(void); diff --git a/drivers/base/core.c b/drivers/base/core.c index d22d6b23e7589..a54ec6df1058f 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; } diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c index b9a34c3425ecf..e83503bdc1fdb 100644 --- a/drivers/base/power/main.c +++ b/drivers/base/power/main.c @@ -278,7 +278,8 @@ static void dpm_wait_for_suppliers(struct device *dev, bool async) * walking. */ dev_for_each_link_to_supplier(link, dev) - if (READ_ONCE(link->status) != DL_STATE_DORMANT) + if (READ_ONCE(link->status) != DL_STATE_DORMANT && + !device_link_flag_is_sync_state_only(link->flags)) dpm_wait(link->supplier, async); device_links_read_unlock(idx); @@ -335,7 +336,8 @@ static void dpm_wait_for_consumers(struct device *dev, bool async) * unregistration). */ dev_for_each_link_to_consumer(link, dev) - if (READ_ONCE(link->status) != DL_STATE_DORMANT) + if (READ_ONCE(link->status) != DL_STATE_DORMANT && + !device_link_flag_is_sync_state_only(link->flags)) dpm_wait(link->consumer, async); device_links_read_unlock(idx); -- 2.51.0