From patchwork Mon Oct 22 10:14:05 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Sean Young X-Patchwork-Id: 10651895 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 84CD7109C for ; Mon, 22 Oct 2018 10:14:09 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6A9AB288EA for ; Mon, 22 Oct 2018 10:14:09 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 5E47A288ED; Mon, 22 Oct 2018 10:14:09 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B33E0288EA for ; Mon, 22 Oct 2018 10:14:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728530AbeJVScA (ORCPT ); Mon, 22 Oct 2018 14:32:00 -0400 Received: from gofer.mess.org ([88.97.38.141]:43751 "EHLO gofer.mess.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727045AbeJVScA (ORCPT ); Mon, 22 Oct 2018 14:32:00 -0400 Received: by gofer.mess.org (Postfix, from userid 1000) id 03A0E601E4; Mon, 22 Oct 2018 11:14:05 +0100 (BST) Date: Mon, 22 Oct 2018 11:14:05 +0100 From: Sean Young To: Torbjorn Jansson Cc: Hans Verkuil , Linux Media Mailing List , stable@vger.kernel.org Subject: [PATCH] media: rc: cec devices do not have a lirc chardev Message-ID: <20181022101405.v7setqacuftrafrb@gofer.mess.org> References: <20181022085910.2gndxc75zcqkto5z@gofer.mess.org> <1a63a5b5-644f-cef4-d0ad-9ae3bf491f9a@mbox200.swipnet.se> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1a63a5b5-644f-cef4-d0ad-9ae3bf491f9a@mbox200.swipnet.se> User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP On Mon, Oct 22, 2018 at 11:44:22AM +0200, Torbjorn Jansson wrote: > On 2018-10-22 10:59, Sean Young wrote: > > On Sat, Oct 20, 2018 at 11:12:16PM +0200, Hans Verkuil wrote: > > > Hi Sean, > > > > > > Can you take a look at this, it appears to be an RC issue, see my analysis below. > > > > > > On 10/20/2018 03:26 PM, Torbjorn Jansson wrote: > > > > Hello > > > > > > > > i'm using the pulse8 usb cec adapter to control my tv. > > > > i have a few scripts that poll the power status of my tv and after a while it stops working returning errors when trying to check if tv is on or off. > > > > this i think matches a kernel oops i'm seeing that i suspect is related to this. > > > > > > > > i have sometimes been able to recover from this problem by completely cutting power to my tv and also unplugging the usb cec adapter. > > > > i have a feeling that the tv is at least partly to blame for cec-ctl not working but in any case there shouldn't be a kernel oops. > > > > > > > > > > > > also every now and then i see this in dmesg: > > > > cec cec0: transmit: failed 05 > > > > cec cec0: transmit: failed 06 > > > > but that doesn't appear to do any harm as far as i can tell. > > > > > > > > any idea whats causing the oops? > > > > > > > > the ops: > > > > > > > > BUG: unable to handle kernel NULL pointer dereference at 0000000000000038 > > > > PGD 0 P4D 0 > > > > Oops: 0000 [#1] SMP PTI > > > > CPU: 9 PID: 27687 Comm: kworker/9:2 Tainted: P           OE 4.18.12-200.fc28.x86_64 #1 > > > > Hardware name: Supermicro C7X99-OCE-F/C7X99-OCE-F, BIOS 2.1a 06/15/2018 > > > > Workqueue: events pulse8_irq_work_handler [pulse8_cec] > > > > RIP: 0010:ir_lirc_scancode_event+0x3d/0xb0 [rc_core] > > > > > > Huh. ir_lirc_scancode_event() calls spin_lock_irqsave(&dev->lirc_fh_lock, flags); > > > > > > The spinlock dev->lirc_fh_lock is initialized in ir_lirc_register(), which is called > > > from rc_register_device(), except when the protocol is CEC: > > > > > > /* Ensure that the lirc kfifo is setup before we start the thread */ > > > if (dev->allowed_protocols != RC_PROTO_BIT_CEC) { > > > rc = ir_lirc_register(dev); > > > if (rc < 0) > > > goto out_rx; > > > } > > > > > > So it looks like ir_lirc_scancode_event() fails because dev->lirc_fh_lock was never > > > initialized. > > > > > > Could this be fall-out from the lirc changes you did not too long ago? > > > > Yes, this is broken. My bad, sorry. I think this must have been broken since > > v4.16. I can write a patch but I don't have a patch but I'm on the train > > to ELCE in Edinburgh now, with no hardware to test on. > > > > > > Sean > > > > the kernel oops have been happening for a while now. > yesterday when i checked my logs i can see them at least back a couple of > months when i was running 4.17 > > also my scripts to poll status of my tv and turn it on/off works for a while > so it doesn't crash right away. > maybe it only crashes when i send cec command to turn on/off tv and only > polling for status is no problem. > > > i think i have a separate issue too because i had problems even before the > kernel oopses started. > but i suspect this is caused by my tv locking up the cec bus because > unplugging power to tv for a few minutes (i must wait or it will still be > just as broken) and then back used to resolve the cec errors from my > scripts. Would you be able to test the following patch please? Thanks, Sean --- From 1b8b20b606b30c0e301c80e18af8d77194269bc1 Mon Sep 17 00:00:00 2001 From: Sean Young Date: Mon, 22 Oct 2018 10:01:50 +0100 Subject: [PATCH] media: rc: cec devices do not have a lirc chardev MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This fixes an oops in ir_lirc_scancode_event(). BUG: unable to handle kernel NULL pointer dereference at 0000000000000038 PGD 0 P4D 0 Oops: 0000 [#1] SMP PTI CPU: 9 PID: 27687 Comm: kworker/9:2 Tainted: P           OE 4.18.12-200.fc28.x86_64 #1 Hardware name: Supermicro C7X99-OCE-F/C7X99-OCE-F, BIOS 2.1a 06/15/2018 Workqueue: events pulse8_irq_work_handler [pulse8_cec] RIP: 0010:ir_lirc_scancode_event+0x3d/0xb0 [rc_core] Code: 8d ae b4 07 00 00 49 81 c6 b8 07 00 00 53 e8 4a df c3 d5 48 89 ef 49 89 45 00 e8 4e 84 41 d6 49 8b 1e 49 89 c4 4c 39 f3 74 58 <8b> 43 38 8b 53 40 89 c1 2b 4b 3c 39 ca 72 41 21 d0 49 8b 7d 00 49 RSP: 0018:ffffaa10e3c07d58 EFLAGS: 00010017 RAX: 0000000000000002 RBX: 0000000000000000 RCX: 0000000000000018 RDX: 0000000000000001 RSI: 00316245397fa93c RDI: ffff966d31c8d7b4 RBP: ffff966d31c8d7b4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000003 R11: ffffaa10e3c07e28 R12: 0000000000000002 R13: ffffaa10e3c07d88 R14: ffff966d31c8d7b8 R15: 0000000000000073 FS:  0000000000000000(0000) GS:ffff966d3f440000(0000) knlGS:0000000000000000 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000038 CR3: 00000009d820a003 CR4: 00000000003606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace:  ir_do_keydown+0x75/0x260 [rc_core]  rc_keydown+0x54/0xc0 [rc_core]  cec_received_msg_ts+0xaa8/0xaf0 [cec]  process_one_work+0x1a1/0x350  worker_thread+0x30/0x380  ? pwq_unbound_release_workfn+0xd0/0xd0  kthread+0x112/0x130  ? kthread_create_worker_on_cpu+0x70/0x70  ret_from_fork+0x35/0x40 Modules linked in: rc_tt_1500 dvb_usb_dvbsky dvb_usb_v2 uas usb_storage fuse vhost_net vhost tap xt_CHECKSUM iptable_mangle ip6t_REJECT nf_reject_ipv6 tun 8021q garp mrp xt_nat macvlan xfs devlink ebta  si2157 si2168 cx25840 cx23885 kvm altera_ci tda18271 joydev ir_rc6_decoder rc_rc6_mce crct10dif_pclmul crc32_pclmul ghash_clmulni_intel intel_cstate intel_uncore altera_stapl m88ds3103 tveeprom cx2341  mxm_wmi igb crc32c_intel megaraid_sas dca i2c_algo_bit wmi vfio_pci irqbypass vfio_virqfd vfio_iommu_type1 vfio i2c_dev CR2: 0000000000000038 Cc: # v4.16+ Signed-off-by: Sean Young --- drivers/media/rc/rc-main.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/media/rc/rc-main.c b/drivers/media/rc/rc-main.c index 552bbe82a160..877978dbd409 100644 --- a/drivers/media/rc/rc-main.c +++ b/drivers/media/rc/rc-main.c @@ -695,7 +695,8 @@ void rc_repeat(struct rc_dev *dev) (dev->last_toggle ? LIRC_SCANCODE_FLAG_TOGGLE : 0) }; - ir_lirc_scancode_event(dev, &sc); + if (dev->allowed_protocols != RC_PROTO_BIT_CEC) + ir_lirc_scancode_event(dev, &sc); spin_lock_irqsave(&dev->keylock, flags); @@ -735,7 +736,8 @@ static void ir_do_keydown(struct rc_dev *dev, enum rc_proto protocol, .keycode = keycode }; - ir_lirc_scancode_event(dev, &sc); + if (dev->allowed_protocols != RC_PROTO_BIT_CEC) + ir_lirc_scancode_event(dev, &sc); if (new_event && dev->keypressed) ir_do_keyup(dev, false);