From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5807DC10F11 for ; Sat, 13 Apr 2019 17:23:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1C1562147A for ; Sat, 13 Apr 2019 17:23:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727065AbfDMRX2 convert rfc822-to-8bit (ORCPT ); Sat, 13 Apr 2019 13:23:28 -0400 Received: from mail.wl.linuxfoundation.org ([198.145.29.98]:43394 "EHLO mail.wl.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727042AbfDMRX2 (ORCPT ); Sat, 13 Apr 2019 13:23:28 -0400 Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 245A428C4D for ; Sat, 13 Apr 2019 17:23:27 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 18D5F28C2C; Sat, 13 Apr 2019 17:23:27 +0000 (UTC) From: bugzilla-daemon@bugzilla.kernel.org To: linux-bluetooth@vger.kernel.org Subject: [Bug 199035] BCM2046B1 and hid2hci generates highcpu usage due to udev since 4.14 kernel Date: Sat, 13 Apr 2019 17:23:25 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Drivers X-Bugzilla-Component: Bluetooth X-Bugzilla-Version: 2.5 X-Bugzilla-Keywords: X-Bugzilla-Severity: high X-Bugzilla-Who: jgwphd@yahoo.com X-Bugzilla-Status: NEW X-Bugzilla-Resolution: X-Bugzilla-Priority: P1 X-Bugzilla-Assigned-To: linux-bluetooth@vger.kernel.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT X-Bugzilla-URL: https://bugzilla.kernel.org/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-Virus-Scanned: ClamAV using ClamSMTP Sender: linux-bluetooth-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-bluetooth@vger.kernel.org https://bugzilla.kernel.org/show_bug.cgi?id=199035 --- Comment #14 from John (jgwphd@yahoo.com) --- An update: The problem I reported in January went away on its own after a few weeks of having the problem every single day when I booted each morning. I was installing Ubuntu software updates when they became available during that time. There is something going on during boot that causes this problem. "my speculation" is that I suspect a timing issue with the way things are initialized during boot up that leads to the problem. Some strange timing issue is occurring which causes systemd-udevd to fall into an infinite loop (continuously looking for something or to be notified about an action completion) and drive one of the processor cores to 100%. When a new kernel was installed or something was done to change initialization activity during boot the problem went away because the timing problem that created it was changed. I believe that some kind of race condition may be at the root of the problem. >From my earlier search on the problem symptoms, it seems that when systemd-udevd isn't working correctly you can get numerous confusing symptoms that mysteriously go away when the something changes timing conditions during boot. Since the problem is in the kernel then it effects other systems besides Ubuntu. -- You are receiving this mail because: You are the assignee for the bug.