Return-path: Received: from mail-oi0-f51.google.com ([209.85.218.51]:36860 "EHLO mail-oi0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752844AbbJAPmQ (ORCPT ); Thu, 1 Oct 2015 11:42:16 -0400 Subject: Re: rtl8821ae bisected regression between 4.1 and 4.2 To: =?UTF-8?Q?Jo=c3=a3o_Paulo_Rechi_Vita?= , linux-wireless References: Cc: Vincent Fann , Shao Fu , Kalle Valo , Stable , Daniel Drake From: Larry Finger Message-ID: <560D5455.8060400@lwfinger.net> (sfid-20151001_174220_928835_85E36087) Date: Thu, 1 Oct 2015 10:42:13 -0500 MIME-Version: 1.0 In-Reply-To: Content-Type: multipart/mixed; boundary="------------040702090205060700050408" Sender: linux-wireless-owner@vger.kernel.org List-ID: This is a multi-part message in MIME format. --------------040702090205060700050408 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit 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. Larry --------------040702090205060700050408 Content-Type: text/x-patch; name="0001-rtlwifi-rtl8821ae-Trial-patch-to-reinstall-interrupt.patch" Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename*0="0001-rtlwifi-rtl8821ae-Trial-patch-to-reinstall-interrupt.pa"; filename*1="tch" >From 97ecd2789dc71b158467fc57d0326641a4581f0d Mon Sep 17 00:00:00 2001 From: Larry Finger Date: Thu, 1 Oct 2015 10:37:49 -0500 Subject: [PATCH] rtlwifi: rtl8821ae: Trial patch to reinstall interrupt clear routine Signed-off-by: Larry Finger --- drivers/net/wireless/rtlwifi/rtl8821ae/hw.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/drivers/net/wireless/rtlwifi/rtl8821ae/hw.c b/drivers/net/wireless/rtlwifi/rtl8821ae/hw.c index b7f18e21..6d2caa8 100644 --- a/drivers/net/wireless/rtlwifi/rtl8821ae/hw.c +++ b/drivers/net/wireless/rtlwifi/rtl8821ae/hw.c @@ -2253,11 +2253,27 @@ void rtl8821ae_set_qos(struct ieee80211_hw *hw, int aci) } } +static void rtl8821ae_clear_interrupt(struct ieee80211_hw *hw) +{ + struct rtl_priv *rtlpriv = rtl_priv(hw); + u32 tmp = rtl_read_dword(rtlpriv, REG_HISR); + + rtl_write_dword(rtlpriv, REG_HISR, tmp); + + tmp = rtl_read_dword(rtlpriv, REG_HISRE); + rtl_write_dword(rtlpriv, REG_HISRE, tmp); + + tmp = rtl_read_dword(rtlpriv, REG_HSISR); + rtl_write_dword(rtlpriv, REG_HSISR, tmp); +} + void rtl8821ae_enable_interrupt(struct ieee80211_hw *hw) { struct rtl_priv *rtlpriv = rtl_priv(hw); struct rtl_pci *rtlpci = rtl_pcidev(rtl_pcipriv(hw)); + rtl8821ae_clear_interrupt(hw);/*clear it here first*/ + rtl_write_dword(rtlpriv, REG_HIMR, rtlpci->irq_mask[0] & 0xFFFFFFFF); rtl_write_dword(rtlpriv, REG_HIMRE, rtlpci->irq_mask[1] & 0xFFFFFFFF); rtlpci->irq_enabled = true; -- 2.1.4 --------------040702090205060700050408--