Return-path: Received: from tartarus.angband.pl ([89.206.35.136]:41872 "EHLO tartarus.angband.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751220AbeFHKn0 (ORCPT ); Fri, 8 Jun 2018 06:43:26 -0400 Date: Fri, 8 Jun 2018 12:43:23 +0200 From: Adam Borowski To: Jakub Kicinski , linux-wireless@vger.kernel.org Subject: WARNING: drivers/net/wireless/mediatek/mt7601u/phy.c:989 Message-ID: <20180608104323.vaw6vtbmxdut6yld@angband.pl> (sfid-20180608_124330_733976_F56990B7) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Sender: linux-wireless-owner@vger.kernel.org List-ID: Hi! In mid-merge-window kernel I'm getting this warning in mt7601. My tree, skipping certainly irrelevant extra patches, has merge-base with master at 289cf155d95df07ac1e692dfaa7036f10235c77c. static void mt7601u_agc_tune(struct mt7601u_dev *dev) { u8 val = mt7601u_agc_default(dev); long avg_rssi; if (test_bit(MT7601U_STATE_SCANNING, &dev->state)) return; /* Note: only in STA mode and not dozing; perhaps do this only if * there is enough rssi updates since last run? * Rssi updates are only on beacons and U2M so should work... */ spin_lock_bh(&dev->con_mon_lock); avg_rssi = ewma_rssi_read(&dev->avg_rssi); ====> WARN_ON_ONCE(avg_rssi == 0); avg_rssi = -avg_rssi; WARNING: CPU: 4 PID: 109 at drivers/net/wireless/mediatek/mt7601u/phy.c:989 mt7601u_phy_calibrate+0x58b/0xaa0 [mt7601u] Modules linked in: arc4 mt7601u mac80211 sha256_generic snd_usb_audio snd_usbmidi_lib cfg80211 rfkill nouveau video ttm CPU: 4 PID: 109 Comm: kworker/u12:7 Not tainted 4.17.0-debug-07836-ga3643eb8ca3a #1 Hardware name: System manufacturer System Product Name/M4A77T, BIOS 2401 05/18/2011 Workqueue: phy0 mt7601u_phy_calibrate [mt7601u] RIP: 0010:mt7601u_phy_calibrate+0x58b/0xaa0 [mt7601u] Code: be b2 00 00 00 48 89 ef 0f 84 da 00 00 00 e8 1c f2 ff ff 83 f8 01 19 c0 25 00 e0 ff ff 45 8d bc 07 66 46 00 00 e9 93 fc ff ff <0f> 0b e9 ba fe ff ff 8b 83 f0 07 00 00 e9 5d fc ff ff c0 e8 04 4d RSP: 0018:ffffc90001febe10 EFLAGS: 00010256 RAX: 0000000000000000 RBX: ffff8802200f95d0 RCX: ffff88022700c020 RDX: 0000000000000001 RSI: ffff88021ffac0b0 RDI: ffff8802200f9d20 RBP: ffff8802200f9500 R08: 8080808080808080 R09: fefefefefefefeff R10: ffffffff8287baf0 R11: 000000000000001f R12: 0000000000000034 R13: ffff8802200f9d20 R14: ffff88021f80de00 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88022fd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000563bf575c168 CR3: 00000002259ed000 CR4: 00000000000006e0 Call Trace: ? process_one_work+0x239/0x680 ? pwq_activate_delayed_work+0x5c/0x100 ? worker_thread+0x4a/0x4b0 ? process_one_work+0x680/0x680 ? kthread+0x16b/0x220 ? kthread_create_worker_on_cpu+0x40/0x40 ? ret_from_fork+0x22/0x40 ---[ end trace e40c73f71a371719 ]--- As bisecting on real metal is more involved than a VM, I'm reporting first -- in case you already have a fix pending. If not, how may I help? Bisect? Some extra debug data? Or, would you prefer to wait until the merge window is over? Meow! -- ⢀⣴⠾⠻⢶⣦⠀ I've read an article about how lively happy music boosts ⣾⠁⢰⠒⠀⣿⡁ productivity. You can read it, too, you just need the ⢿⡄⠘⠷⠚⠋⠀ right music while doing so. I recommend Skepticism ⠈⠳⣄⠀⠀⠀⠀ (funeral doom metal).