From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ben Hutchings Subject: [ 27/98] sfc: Disable soft interrupt handling during efx_device_detach_sync() Date: Tue, 26 Mar 2013 15:42:16 -0700 Message-Id: <20130326224245.262560870@linuxfoundation.org> In-Reply-To: <20130326224242.449070940@linuxfoundation.org> References: <20130326224242.449070940@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.8-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: Greg Kroah-Hartman --- drivers/net/ethernet/sfc/efx.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/net/ethernet/sfc/efx.h +++ b/drivers/net/ethernet/sfc/efx.h @@ -171,9 +171,9 @@ static inline void efx_device_detach_syn * 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 */