Return-path: Received: from mail-wg0-f44.google.com ([74.125.82.44]:41156 "EHLO mail-wg0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753270AbbCCGkS convert rfc822-to-8bit (ORCPT ); Tue, 3 Mar 2015 01:40:18 -0500 Received: by wghl18 with SMTP id l18so37926105wgh.8 for ; Mon, 02 Mar 2015 22:40:17 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <1425350171-26333-1-git-send-email-xerofoify@gmail.com> References: <1425350171-26333-1-git-send-email-xerofoify@gmail.com> Date: Tue, 3 Mar 2015 07:40:17 +0100 Message-ID: (sfid-20150303_074055_764729_2C99FC96) Subject: Re: [PATCH] ath:Release resources for structure pointer, ar if error pointing device in the function, ath10k_core_register_work From: Michal Kazior To: Nicholas Krause Cc: Kalle Valo , Network Development , linux-wireless , linux-kernel@vger.kernel.org, "ath10k@lists.infradead.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-wireless-owner@vger.kernel.org List-ID: On 3 March 2015 at 03:36, Nicholas Krause wrote: > Releases resources and deregisters the stucture pointer ar passed by the caller to the function, ath10k_core_register_work > if unable to probe the structure pointer successfully with a call to ath10k_core_probe_fw. Further more if this happerns > we must first jump to the label err for the goto statement required to jump to handle this particular error in the function, > ath10k_core_register_work. After we are in the correct error section we must free the resources for the structure pointer,ar > with a call to the function, ath10k_core_unregister to free resources allocated for the structure pointer,ar. > > Signed-off-by: Nicholas Krause > --- > drivers/net/wireless/ath/ath10k/core.c | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) > > diff --git a/drivers/net/wireless/ath/ath10k/core.c b/drivers/net/wireless/ath/ath10k/core.c > index 310e12b..8b2ca25 100644 > --- a/drivers/net/wireless/ath/ath10k/core.c > +++ b/drivers/net/wireless/ath/ath10k/core.c > @@ -1307,9 +1307,7 @@ err_unregister_mac: > err_release_fw: > ath10k_core_free_firmware_files(ar); > err: > - /* TODO: It's probably a good idea to release device from the driver > - * but calling device_release_driver() here will cause a deadlock. > - */ > + ath10k_core_unregister(ar); > return; > } Did you test this? This will deadlock. ath10k_core_unregister() tries to cancel ar->register_work. This won't work if you call it from the worker itself. Moreover if I ignore the deadlock ath10k_core_unregister() would do nothing else in this context because ATH10K_FLAG_CORE_REGISTERED wouldn't be even set. If you're interested in dealing with this TODO I suggest you read through the original thread which led to the current state of affairs: http://www.spinics.net/lists/linux-wireless/msg124004.html Michał