Return-path: Received: from mail-oi0-f42.google.com ([209.85.218.42]:36759 "EHLO mail-oi0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932671AbcA2RyM (ORCPT ); Fri, 29 Jan 2016 12:54:12 -0500 Subject: Re: WARNING at net/mac80211/rate.c:513 ieee80211_get_tx_rates [mac80211] To: Linus Torvalds References: <1453983185.2217.12.camel@sipsolutions.net> <1454013625.2332.9.camel@sipsolutions.net> <1454019155.2332.15.camel@sipsolutions.net> <56AAC66C.1080800@lwfinger.net> <1454056380.3369.2.camel@sipsolutions.net> <1454084146.2800.0.camel@sipsolutions.net> Cc: Johannes Berg , Chaoming Li , Kalle Valo , David Miller , Linux Wireless List , Network Development From: Larry Finger Message-ID: <56ABA73C.1060504@lwfinger.net> (sfid-20160129_185452_503497_4BCCF969) Date: Fri, 29 Jan 2016 11:54:04 -0600 MIME-Version: 1.0 In-Reply-To: <1454084146.2800.0.camel@sipsolutions.net> Content-Type: multipart/mixed; boundary="------------010908040302070206000802" Sender: linux-wireless-owner@vger.kernel.org List-ID: This is a multi-part message in MIME format. --------------010908040302070206000802 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Linus, Attached is a trial patch that fixes the problem on my system. As I told Johannes earlier, my AP was not configured to use VHT, thus I did not see the problem. The test patch that Johannes sent earlier was close. The section needed to add VHT rates is: --- a/drivers/net/wireless/realtek/rtlwifi/rc.c +++ b/drivers/net/wireless/realtek/rtlwifi/rc.c @@ -138,6 +138,9 @@ static void _rtl_rc_rate_set_series(struct rtl_priv *rtlpriv, ((wireless_mode == WIRELESS_MODE_N_5G) || (wireless_mode == WIRELESS_MODE_N_24G))) rate->flags |= IEEE80211_TX_RC_MCS; + if (sta && sta->vht_cap.vht_supported && + (wireless_mode == WIRELESS_MODE_AC_5G)) + rate->flags |= IEEE80211_TX_RC_VHT_MCS; } } Larry --------------010908040302070206000802 Content-Type: text/x-patch; name="0001-rtlwifi-Fix-warning-from-ieee80211_get_tx_rates-when.patch" Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename*0="0001-rtlwifi-Fix-warning-from-ieee80211_get_tx_rates-when.pa"; filename*1="tch" >From bd34ac0c3caa9ff982194256b0e96772a17e719d Mon Sep 17 00:00:00 2001 From: Larry Finger Date: Fri, 29 Jan 2016 11:29:10 -0600 Subject: [PATCH] rtlwifi: Fix warning from ieee80211_get_tx_rates() when using 5G To: kvalo@codeaurora.org Cc: linux-wireless@vger.kernel.org, devel@driverdev.osuosl.org When using a 5G-capable device with VHT rates enabled, the following warning results: WARNING: CPU: 3 PID: 2253 at net/mac80211/rate.c:625 ieee80211_get_tx_rates+0x22e/0x620 [mac80211]() Modules linked in: rtl8821ae btcoexist rtl_pci rtlwifi fuse drbg ansi_cprng ctr ccm bnep bluetooth af_packet nfs fscache vboxpci(O) vboxnetadp(O) vboxne tflt(O) vboxdrv(O) arc4 snd_hda_codec_generic x86_pkg_temp_thermal rtsx_pci_sdmmc mmc_core rtsx_pci_ms kvm_intel memstick iwlmvm kvm mac80211 snd_hda_intel snd_hda_cod ec snd_hwdep snd_hda_core irqbypass snd_pcm iwlwifi crct10dif_pclmul crc32_pclmul crc32c_intel ghash_clmulni_intel aesni_intel aes_x86_64 snd_timer lrw gf128mul glue_h elper ablk_helper cryptd snd cfg80211 pcspkr serio_raw e1000e rtsx_pci lpc_ich ptp xhci_pci mfd_core pps_core xhci_hcd soundcore toshiba_acpi thermal sparse_keymap wmi toshiba_bluetooth rfkill acpi_cpufreq battery ac processor dm_mod i915 i2c_algo_bit drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops drm sr_mod cdrom video button sg autofs4 [last unloaded: rtlwifi] CPU: 3 PID: 2253 Comm: Timer Tainted: G W O 4.5.0-rc1-wl+ #79 Hardware name: TOSHIBA TECRA A50-A/TECRA A50-A, BIOS Version 4.20 04/17/2014 ffffffffa05c4be6 ffff8802262036d8 ffffffff813d7912 0000000000000000 ffff880226203710 ffffffff8106bcb6 ffff8800c6831300 ffff8800c6831330 0000000000000000 ffff8800c683133c ffff880065923638 ffff880226203720 Call Trace: [] dump_stack+0x4b/0x79 [] warn_slowpath_common+0x86/0xc0 [] warn_slowpath_null+0x1a/0x20 [] ieee80211_get_tx_rates+0x22e/0x620 [mac80211] [] ? rtl_is_special_data+0x32/0x240 [rtlwifi] [] ? rate_control_get_rate+0xce/0x150 [mac80211] [] ? trace_hardirqs_on+0xd/0x10 [] ? __local_bh_enable_ip+0x65/0xd0 --- traceback terminated here --- The problem is that IEEE80211_TX_RC_VHT_MCS is not set in the rate flags. Reported-by: Linus Torvalds Cc: Johannes Berg Signed-off-by: Larry Finger Cc: Stable --- drivers/net/wireless/realtek/rtlwifi/rc.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/net/wireless/realtek/rtlwifi/rc.c b/drivers/net/wireless/realtek/rtlwifi/rc.c index 74c14ce..e7eae63 100644 --- a/drivers/net/wireless/realtek/rtlwifi/rc.c +++ b/drivers/net/wireless/realtek/rtlwifi/rc.c @@ -138,6 +138,9 @@ static void _rtl_rc_rate_set_series(struct rtl_priv *rtlpriv, ((wireless_mode == WIRELESS_MODE_N_5G) || (wireless_mode == WIRELESS_MODE_N_24G))) rate->flags |= IEEE80211_TX_RC_MCS; + if (sta && sta->vht_cap.vht_supported && + (wireless_mode == WIRELESS_MODE_AC_5G)) + rate->flags |= IEEE80211_TX_RC_VHT_MCS; } } -- 2.1.4 --------------010908040302070206000802--