From patchwork Mon Jul 18 20:52:13 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Wang X-Patchwork-Id: 12921764 X-Patchwork-Delegate: nbd@nbd.name 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 1A7D5CCA479 for ; Mon, 18 Jul 2022 20:52:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235141AbiGRUw1 (ORCPT ); Mon, 18 Jul 2022 16:52:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52888 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235067AbiGRUwZ (ORCPT ); Mon, 18 Jul 2022 16:52:25 -0400 Received: from mailgw02.mediatek.com (unknown [210.61.82.184]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 70850326DB for ; Mon, 18 Jul 2022 13:52:24 -0700 (PDT) X-UUID: 622ecece87204d259fac9b3424429de0-20220719 X-CID-P-RULE: Release_Ham X-CID-O-INFO: VERSION:1.1.8,REQID:a382244a-9818-4005-8a2d-01634ffa64b0,OB:0,LO B:0,IP:0,URL:5,TC:0,Content:0,EDM:0,RT:0,SF:0,FILE:0,RULE:Release_Ham,ACTI ON:release,TS:5 X-CID-META: VersionHash:0f94e32,CLOUDID:e94d9e64-0b3f-4b2c-b3a6-ed5c044366a0,C OID:IGNORED,Recheck:0,SF:nil,TC:nil,Content:0,EDM:-3,IP:nil,URL:1,File:nil ,QS:nil,BEC:nil,COL:0 X-UUID: 622ecece87204d259fac9b3424429de0-20220719 Received: from mtkmbs10n2.mediatek.inc [(172.21.101.183)] by mailgw02.mediatek.com (envelope-from ) (Generic MTA with TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384 256/256) with ESMTP id 1145465249; Tue, 19 Jul 2022 04:52:19 +0800 Received: from mtkmbs11n2.mediatek.inc (172.21.101.187) by mtkmbs11n1.mediatek.inc (172.21.101.185) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.792.3; Tue, 19 Jul 2022 04:52:17 +0800 Received: from mtkswgap22.mediatek.inc (172.21.77.33) by mtkmbs11n2.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.2.792.3 via Frontend Transport; Tue, 19 Jul 2022 04:52:17 +0800 From: To: , CC: , , , , , , , , , , , , , , , , , , , , , , , Subject: [PATCH 1/3] mt76: mt7921s: fix the deadlock caused by sdio->stat_work Date: Tue, 19 Jul 2022 04:52:13 +0800 Message-ID: X-Mailer: git-send-email 1.7.9.5 MIME-Version: 1.0 X-MTK: N Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org From: Sean Wang Because wake_work and sdio->stat_work share the same workqueue mt76->wq, if sdio->stat_work cannot acquire the mutex lock such as that was possibly held up by mt7921_mutex_acquire, we should exit immediately and schedule another stat_work to avoid blocking the mt7921_mutex_acquire. Also, if mt7921_mutex_acquire was called by sdio->stat_work self, the wake would be blocked by itself, so we have to changing into an unblocking wake (directly wakeup via mt7921_mcu_drv_pmctrl, not via the wake_work) in the context. Fixes: 48fab5bbef40 ("mt76: mt7921: introduce mt7921s support") Co-developed-by: YN Chen Signed-off-by: YN Chen Signed-off-by: Sean Wang --- .../net/wireless/mediatek/mt76/mt7921/mac.c | 22 +++++++++++++++++-- 1 file changed, 20 insertions(+), 2 deletions(-) diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/mac.c b/drivers/net/wireless/mediatek/mt76/mt7921/mac.c index 6bd9fc9228a2..75e719175e92 100644 --- a/drivers/net/wireless/mediatek/mt76/mt7921/mac.c +++ b/drivers/net/wireless/mediatek/mt76/mt7921/mac.c @@ -1080,10 +1080,28 @@ bool mt7921_usb_sdio_tx_status_data(struct mt76_dev *mdev, u8 *update) { struct mt7921_dev *dev = container_of(mdev, struct mt7921_dev, mt76); - mt7921_mutex_acquire(dev); + if (!mutex_trylock(&mdev->mutex)) { + /* Because wake_work and stat_work share the same workqueue + * mt76->wq, if sdio->stat_work cannot acquire the mutex lock, + * we should exit immediately and schedule another stat_work + * to avoid blocking the wake_work. + */ + struct work_struct *stat_work; + + stat_work = mt76_is_sdio(mdev) ? &mdev->sdio.stat_work : + &mdev->usb.stat_work; + queue_work(dev->mt76.wq, stat_work); + + goto out; + } + + mt7921_mcu_drv_pmctrl(dev); mt7921_mac_sta_poll(dev); - mt7921_mutex_release(dev); + mt76_connac_power_save_sched(&mdev->phy, &dev->pm); + mutex_unlock(&mdev->mutex); + +out: return false; } EXPORT_SYMBOL_GPL(mt7921_usb_sdio_tx_status_data);