Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CBBFBC10F14 for ; Tue, 16 Apr 2019 09:13:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A560220675 for ; Tue, 16 Apr 2019 09:13:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728684AbfDPJN3 (ORCPT ); Tue, 16 Apr 2019 05:13:29 -0400 Received: from mx1.redhat.com ([209.132.183.28]:44352 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726160AbfDPJN2 (ORCPT ); Tue, 16 Apr 2019 05:13:28 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 48A1D81E13; Tue, 16 Apr 2019 09:13:28 +0000 (UTC) Received: from localhost (unknown [10.40.205.155]) by smtp.corp.redhat.com (Postfix) with ESMTP id A045D60C5F; Tue, 16 Apr 2019 09:13:25 +0000 (UTC) From: Stanislaw Gruszka To: linux-wireless@vger.kernel.org Cc: Felix Fietkau , Lorenzo Bianconi Subject: [RFC 3/3] mt76x02: remove bogus mutex usage Date: Tue, 16 Apr 2019 11:13:05 +0200 Message-Id: <20190416091305.4218-4-sgruszka@redhat.com> In-Reply-To: <20190416091305.4218-1-sgruszka@redhat.com> References: <20190416091305.4218-1-sgruszka@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.25]); Tue, 16 Apr 2019 09:13:28 +0000 (UTC) Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org mac .start(), .stop() callbacks are never called concurrently with other mac callbacks. The only concurencly is with mt76 works which we cancel on stop() and schedule on start(). This fixes possible deadlock on cancel_delayed_work_sync(&dev->mac_work) as mac_work also take mutex. Signed-off-by: Stanislaw Gruszka --- .../net/wireless/mediatek/mt76/mt76x0/pci.c | 6 ----- .../net/wireless/mediatek/mt76/mt76x0/usb.c | 22 +++++-------------- .../wireless/mediatek/mt76/mt76x2/pci_main.c | 5 ----- .../wireless/mediatek/mt76/mt76x2/usb_main.c | 10 ++------- 4 files changed, 7 insertions(+), 36 deletions(-) diff --git a/drivers/net/wireless/mediatek/mt76/mt76x0/pci.c b/drivers/net/wireless/mediatek/mt76/mt76x0/pci.c index 156d3d064ba0..ac979128386a 100644 --- a/drivers/net/wireless/mediatek/mt76/mt76x0/pci.c +++ b/drivers/net/wireless/mediatek/mt76/mt76x0/pci.c @@ -25,8 +25,6 @@ static int mt76x0e_start(struct ieee80211_hw *hw) { struct mt76x02_dev *dev = hw->priv; - mutex_lock(&dev->mt76.mutex); - mt76x02_mac_start(dev); mt76x0_phy_calibrate(dev, true); ieee80211_queue_delayed_work(dev->mt76.hw, &dev->mac_work, @@ -35,8 +33,6 @@ static int mt76x0e_start(struct ieee80211_hw *hw) MT_CALIBRATE_INTERVAL); set_bit(MT76_STATE_RUNNING, &dev->mt76.state); - mutex_unlock(&dev->mt76.mutex); - return 0; } @@ -62,10 +58,8 @@ static void mt76x0e_stop(struct ieee80211_hw *hw) { struct mt76x02_dev *dev = hw->priv; - mutex_lock(&dev->mt76.mutex); clear_bit(MT76_STATE_RUNNING, &dev->mt76.state); mt76x0e_stop_hw(dev); - mutex_unlock(&dev->mt76.mutex); } static void diff --git a/drivers/net/wireless/mediatek/mt76/mt76x0/usb.c b/drivers/net/wireless/mediatek/mt76/mt76x0/usb.c index 22c10722019d..494b9f35f80d 100644 --- a/drivers/net/wireless/mediatek/mt76/mt76x0/usb.c +++ b/drivers/net/wireless/mediatek/mt76/mt76x0/usb.c @@ -81,8 +81,10 @@ static void mt76x0u_cleanup(struct mt76x02_dev *dev) mt76u_queues_deinit(&dev->mt76); } -static void mt76x0u_mac_stop(struct mt76x02_dev *dev) +static void mt76x0u_stop(struct ieee80211_hw *hw) { + struct mt76x02_dev *dev = hw->priv; + clear_bit(MT76_STATE_RUNNING, &dev->mt76.state); cancel_delayed_work_sync(&dev->cal_work); cancel_delayed_work_sync(&dev->mac_work); @@ -106,11 +108,9 @@ static int mt76x0u_start(struct ieee80211_hw *hw) struct mt76x02_dev *dev = hw->priv; int ret; - mutex_lock(&dev->mt76.mutex); - ret = mt76x0_mac_start(dev); if (ret) - goto out; + return ret; mt76x0_phy_calibrate(dev, true); ieee80211_queue_delayed_work(dev->mt76.hw, &dev->mac_work, @@ -118,19 +118,7 @@ static int mt76x0u_start(struct ieee80211_hw *hw) ieee80211_queue_delayed_work(dev->mt76.hw, &dev->cal_work, MT_CALIBRATE_INTERVAL); set_bit(MT76_STATE_RUNNING, &dev->mt76.state); - -out: - mutex_unlock(&dev->mt76.mutex); - return ret; -} - -static void mt76x0u_stop(struct ieee80211_hw *hw) -{ - struct mt76x02_dev *dev = hw->priv; - - mutex_lock(&dev->mt76.mutex); - mt76x0u_mac_stop(dev); - mutex_unlock(&dev->mt76.mutex); + return 0; } static const struct ieee80211_ops mt76x0u_ops = { diff --git a/drivers/net/wireless/mediatek/mt76/mt76x2/pci_main.c b/drivers/net/wireless/mediatek/mt76/mt76x2/pci_main.c index 16dc8e2451b5..1b5caabebff5 100644 --- a/drivers/net/wireless/mediatek/mt76/mt76x2/pci_main.c +++ b/drivers/net/wireless/mediatek/mt76/mt76x2/pci_main.c @@ -22,8 +22,6 @@ mt76x2_start(struct ieee80211_hw *hw) struct mt76x02_dev *dev = hw->priv; int ret; - mutex_lock(&dev->mt76.mutex); - ret = mt76x2_mac_start(dev); if (ret) goto out; @@ -40,7 +38,6 @@ mt76x2_start(struct ieee80211_hw *hw) set_bit(MT76_STATE_RUNNING, &dev->mt76.state); out: - mutex_unlock(&dev->mt76.mutex); return ret; } @@ -49,10 +46,8 @@ mt76x2_stop(struct ieee80211_hw *hw) { struct mt76x02_dev *dev = hw->priv; - mutex_lock(&dev->mt76.mutex); clear_bit(MT76_STATE_RUNNING, &dev->mt76.state); mt76x2_stop_hardware(dev); - mutex_unlock(&dev->mt76.mutex); } static int diff --git a/drivers/net/wireless/mediatek/mt76/mt76x2/usb_main.c b/drivers/net/wireless/mediatek/mt76/mt76x2/usb_main.c index 0771de210c6a..32726b4906ea 100644 --- a/drivers/net/wireless/mediatek/mt76/mt76x2/usb_main.c +++ b/drivers/net/wireless/mediatek/mt76/mt76x2/usb_main.c @@ -21,30 +21,24 @@ static int mt76x2u_start(struct ieee80211_hw *hw) struct mt76x02_dev *dev = hw->priv; int ret; - mutex_lock(&dev->mt76.mutex); - ret = mt76x2u_mac_start(dev); if (ret) - goto out; + return ret; ieee80211_queue_delayed_work(mt76_hw(dev), &dev->mac_work, MT_MAC_WORK_INTERVAL); set_bit(MT76_STATE_RUNNING, &dev->mt76.state); -out: - mutex_unlock(&dev->mt76.mutex); - return ret; + return 0; } static void mt76x2u_stop(struct ieee80211_hw *hw) { struct mt76x02_dev *dev = hw->priv; - mutex_lock(&dev->mt76.mutex); clear_bit(MT76_STATE_RUNNING, &dev->mt76.state); mt76u_stop_tx(&dev->mt76); mt76x2u_stop_hw(dev); - mutex_unlock(&dev->mt76.mutex); } static int -- 2.20.1