From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756913Ab3CYBYp (ORCPT ); Sun, 24 Mar 2013 21:24:45 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:34061 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756061Ab3CYBQM (ORCPT ); Sun, 24 Mar 2013 21:16:12 -0400 Message-Id: <20130325010529.043746724@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Mon, 25 Mar 2013 01:06:12 +0000 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: akpm@linux-foundation.org, Ben Hutchings Subject: [ 048/104] sfc: Disable soft interrupt handling during efx_device_detach_sync() Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit In-Reply-To: <20130325010524.240972766@decadent.org.uk> X-SA-Exim-Connect-IP: 2001:470:1f08:1539:f137:78a:b654:affb X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ben Hutchings [ Upstream commit 35205b211c8d17a8a0b5e8926cb7c73e9a7ef1ad ] efx_device_detach_sync() locks all TX queues before marking the device detached and thus disabling further TX scheduling. But it can still be interrupted by TX completions which then result in TX scheduling in soft interrupt context. This will deadlock when it tries to acquire a TX queue lock that efx_device_detach_sync() already acquired. To avoid deadlock, we must use netif_tx_{,un}lock_bh(). Signed-off-by: Ben Hutchings Signed-off-by: Ben Hutchings --- drivers/net/ethernet/sfc/efx.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/sfc/efx.h b/drivers/net/ethernet/sfc/efx.h index 55e72af..9668d29 100644 --- a/drivers/net/ethernet/sfc/efx.h +++ b/drivers/net/ethernet/sfc/efx.h @@ -157,9 +157,9 @@ static inline void efx_device_detach_sync(struct efx_nic *efx) * TX scheduler is stopped when we're done and before * netif_device_present() becomes false. */ - netif_tx_lock(dev); + netif_tx_lock_bh(dev); netif_device_detach(dev); - netif_tx_unlock(dev); + netif_tx_unlock_bh(dev); } #endif /* EFX_EFX_H */