From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1113DEB64D7 for ; Mon, 26 Jun 2023 14:21:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231315AbjFZOVt (ORCPT ); Mon, 26 Jun 2023 10:21:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38946 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231317AbjFZOVa (ORCPT ); Mon, 26 Jun 2023 10:21:30 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8EA331729 for ; Mon, 26 Jun 2023 07:20:34 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 6A12F60E8C for ; Mon, 26 Jun 2023 14:19:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 720C8C433C0; Mon, 26 Jun 2023 14:19:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1687789169; bh=oQyvsHt4dM8odTAWdioblxJilaNctTipAgDHI9LckMs=; h=Subject:To:Cc:From:Date:From; b=exuZKmu6auJU2AZci0GhyzTkL7bwJX6etCPqLYNAH7TLQzhhEOO3CWOs8z5pw+SYh OeOgnlZR35mo0hwblCTqYZ3unkEiIhZP0sz2ry5xkRfkcrqgcSD+rgyGru2zkpOH5M RWSMVPDGH4WCxNZS/1fO+yWDCrZakZRAoAD07Tyk= Subject: FAILED: patch "[PATCH] wifi: iwlwifi: mvm: spin_lock_bh() to fix lockdep regression" failed to apply to 6.3-stable tree To: hughd@google.com, johannes.berg@intel.com Cc: From: Date: Mon, 26 Jun 2023 16:19:26 +0200 Message-ID: <2023062625-squeamish-trident-4e6a@gregkh> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 6.3-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.3.y git checkout FETCH_HEAD git cherry-pick -x f1a0898b5d6a77d332d036da03bad6fa9770de5b # git commit -s git send-email --to '' --in-reply-to '2023062625-squeamish-trident-4e6a@gregkh' --subject-prefix 'PATCH 6.3.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From f1a0898b5d6a77d332d036da03bad6fa9770de5b Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Fri, 9 Jun 2023 14:29:39 -0700 Subject: [PATCH] wifi: iwlwifi: mvm: spin_lock_bh() to fix lockdep regression Lockdep on 6.4-rc on ThinkPad X1 Carbon 5th says ===================================================== WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected 6.4.0-rc5 #1 Not tainted ----------------------------------------------------- kworker/3:1/49 [HC0[0]:SC0[4]:HE1:SE0] is trying to acquire: ffff8881066fa368 (&mvm_sta->deflink.lq_sta.rs_drv.pers.lock){+.+.}-{2:2}, at: rs_drv_get_rate+0x46/0xe7 and this task is already holding: ffff8881066f80a8 (&sta->rate_ctrl_lock){+.-.}-{2:2}, at: rate_control_get_rate+0xbd/0x126 which would create a new lock dependency: (&sta->rate_ctrl_lock){+.-.}-{2:2} -> (&mvm_sta->deflink.lq_sta.rs_drv.pers.lock){+.+.}-{2:2} but this new dependency connects a SOFTIRQ-irq-safe lock: (&sta->rate_ctrl_lock){+.-.}-{2:2} etc. etc. etc. Changing the spin_lock() in rs_drv_get_rate() to spin_lock_bh() was not enough to pacify lockdep, but changing them all on pers.lock has worked. Fixes: a8938bc881d2 ("wifi: iwlwifi: mvm: Add locking to the rate read flow") Signed-off-by: Hugh Dickins Link: https://lore.kernel.org/r/79ffcc22-9775-cb6d-3ffd-1a517c40beef@google.com Signed-off-by: Johannes Berg diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/rs.c b/drivers/net/wireless/intel/iwlwifi/mvm/rs.c index 23266d0c9ce4..9a20468345e4 100644 --- a/drivers/net/wireless/intel/iwlwifi/mvm/rs.c +++ b/drivers/net/wireless/intel/iwlwifi/mvm/rs.c @@ -2692,7 +2692,7 @@ static void rs_drv_get_rate(void *mvm_r, struct ieee80211_sta *sta, lq_sta = mvm_sta; - spin_lock(&lq_sta->pers.lock); + spin_lock_bh(&lq_sta->pers.lock); iwl_mvm_hwrate_to_tx_rate_v1(lq_sta->last_rate_n_flags, info->band, &info->control.rates[0]); info->control.rates[0].count = 1; @@ -2707,7 +2707,7 @@ static void rs_drv_get_rate(void *mvm_r, struct ieee80211_sta *sta, iwl_mvm_hwrate_to_tx_rate_v1(last_ucode_rate, info->band, &txrc->reported_rate); } - spin_unlock(&lq_sta->pers.lock); + spin_unlock_bh(&lq_sta->pers.lock); } static void *rs_drv_alloc_sta(void *mvm_rate, struct ieee80211_sta *sta, @@ -3264,11 +3264,11 @@ void iwl_mvm_rs_tx_status(struct iwl_mvm *mvm, struct ieee80211_sta *sta, /* If it's locked we are in middle of init flow * just wait for next tx status to update the lq_sta data */ - if (!spin_trylock(&mvmsta->deflink.lq_sta.rs_drv.pers.lock)) + if (!spin_trylock_bh(&mvmsta->deflink.lq_sta.rs_drv.pers.lock)) return; __iwl_mvm_rs_tx_status(mvm, sta, tid, info, ndp); - spin_unlock(&mvmsta->deflink.lq_sta.rs_drv.pers.lock); + spin_unlock_bh(&mvmsta->deflink.lq_sta.rs_drv.pers.lock); } #ifdef CONFIG_MAC80211_DEBUGFS @@ -4117,9 +4117,9 @@ void iwl_mvm_rs_rate_init(struct iwl_mvm *mvm, } else { struct iwl_mvm_sta *mvmsta = iwl_mvm_sta_from_mac80211(sta); - spin_lock(&mvmsta->deflink.lq_sta.rs_drv.pers.lock); + spin_lock_bh(&mvmsta->deflink.lq_sta.rs_drv.pers.lock); rs_drv_rate_init(mvm, sta, band); - spin_unlock(&mvmsta->deflink.lq_sta.rs_drv.pers.lock); + spin_unlock_bh(&mvmsta->deflink.lq_sta.rs_drv.pers.lock); } }