Return-path: Received: from mail-yk0-f169.google.com ([209.85.160.169]:34776 "EHLO mail-yk0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750715AbbJAVIN convert rfc822-to-8bit (ORCPT ); Thu, 1 Oct 2015 17:08:13 -0400 MIME-Version: 1.0 In-Reply-To: <560D5455.8060400@lwfinger.net> References: <560D5455.8060400@lwfinger.net> From: =?UTF-8?Q?Jo=C3=A3o_Paulo_Rechi_Vita?= Date: Thu, 1 Oct 2015 17:07:33 -0400 Message-ID: (sfid-20151001_230825_461903_6AB7CDB0) Subject: Re: rtl8821ae bisected regression between 4.1 and 4.2 To: Larry Finger Cc: linux-wireless , Vincent Fann , Shao Fu , Kalle Valo , Stable , Daniel Drake Content-Type: text/plain; charset=UTF-8 Sender: linux-wireless-owner@vger.kernel.org List-ID: Hello Larry, On 1 October 2015 at 11:42, Larry Finger wrote: > On 10/01/2015 08:17 AM, João Paulo Rechi Vita wrote: >> >> Hello linux-wirelless (cc'ing stable since the original patch had >> cc:stable as well), >> >> I'm experiencing a CPU soft lockup while downloading when rtl8821ae is >> loaded (even when downloading through other adapters) on a vanilla 4.2 >> kernel. The problem did not happen on vanilla 4.1. Bisecting shows the >> first bad commit being "rtlwifi: Remove the clear interrupt routine >> from all drivers" (1277fa2ab2f9a624a4b0177119ca13b5fd65edd0). >> Reverting that commit makes the problem go away. >> >> The system is perfectly stable until I start downloading, when the UI >> becomes unresponsive, sometimes leading to a complete freeze. When the >> system does not completely freezes and I'm able to kill the download, >> everything seems to go back to normal after killing it, and I am able >> to continue to use the computer as long as I do not download anything. >> Most of the time either a soft or a hard lockup is detected, but not >> always, although the freeze always occurs. >> >> This is the kernel log with lockdep enabled (although sometimes the >> problem does not occur with lockdep enabled): >> https://gist.github.com/jprvita/3aa2c0c9a66793e1fad1 >> >> I have the laptop where this happens as a test machine sitting on my >> desk, so I'm available to test any patches or gather more information >> if needed. Please advise on how I can help debugging this further. > > > I cannot duplicate your result, and neither can the Realtek team; however, I > have prepared and attached a patch to temporarily re-add the interrupt clear > routine for rtl8821ae. Please try it and report the results. > With the attached patch the lockup goes away and the system remains stable during downloads. Let me know if there is anything else you would like me to test. Regards, -- João Paulo Rechi Vita http://about.me/jprvita