Return-path: Received: from mail.kernel.org ([198.145.29.136]:33610 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752131AbcHOJkx (ORCPT ); Mon, 15 Aug 2016 05:40:53 -0400 From: Masami Hiramatsu To: Arend van Spriel , Franky Lin , Hante Meuleman , Kalle Valo , Pieter-Paul Giesberts , =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= Cc: linux-wireless@vger.kernel.org, brcm80211-dev-list.pdl@broadcom.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [BUGFIX PATCH 0/2] Bugfixes for brcmfmac Date: Mon, 15 Aug 2016 18:40:41 +0900 Message-Id: <147125403645.9434.8008546579326856373.stgit@devbox> (sfid-20160815_114119_164272_40E9BCEF) MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Sender: linux-wireless-owner@vger.kernel.org List-ID: Hi, Here are 2 patches for fixing bugs which I recently faced on my PC. There are 2 bugs I've hit on brcmfmac, one issue was critical, the other was just found when I investigated the first issue. 1) when I shutdown or reboot my pc with wifi, it always stopped when disabling networking. I tried to just disable wifi and saw task hung up messages on dmesg. All those taskes were blocked on rtnl_lock according to the stacktrace, and found a suspicious task in the list. Actually the wpa_supplicant is blocked while stopping the interface. 2) I also tried to get more information about that and enabled DEBUG_ATOMIC_SLEEP and got another warning in brcmfmac. That warned a mutex (which can yeild/sleep) is held in !TASK_RUNNING state. I've found a mutex is held when in wait_event_timeout() condition parameter. I traced the source code and found that #1 was caused by double locking of rtnl_lock in brcmfmac driver, because it doesn't check the rtnl_lock is already held in a path (actually, other paths checked that). So I fixed it by checking rtnl_locked and skip locking rtnl_lock. It works, but not seems the best way to fix, since original code (rtnl_lock locking around cfg80211_unregister_wdev) itself looks add-hoc. Anyway, since I don't have any knowladge of this subsystem, I'd like to ask maintainer's help. To fix #2 issue, I've checked the mutex (vif_event_lock) in struct brcmf_cfg80211_vif_event just protect updating other members and can be replaced by a spinlock because in the protected regions are not involving any scheduler related code. Thank you, --- Masami Hiramatsu (2): brcmfmac: Check rtnl_lock is locked when removing interface brcmfmac: Change vif_event_lock to spinlock .../broadcom/brcm80211/brcmfmac/cfg80211.c | 26 ++++++++++---------- .../broadcom/brcm80211/brcmfmac/cfg80211.h | 2 +- .../wireless/broadcom/brcm80211/brcmfmac/core.c | 2 +- .../net/wireless/broadcom/brcm80211/brcmfmac/p2p.c | 8 ++++-- .../net/wireless/broadcom/brcm80211/brcmfmac/p2p.h | 2 +- 5 files changed, 21 insertions(+), 19 deletions(-) -- Masami Hiramatsu