From owner-freebsd-usb@freebsd.org Mon Sep 14 03:42:03 2020 Return-Path: Delivered-To: freebsd-usb@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 97C473F093B for ; Mon, 14 Sep 2020 03:42:03 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mailman.nyi.freebsd.org (unknown [127.0.1.3]) by mx1.freebsd.org (Postfix) with ESMTP id 4BqXGz3Yyvz47Jq for ; Mon, 14 Sep 2020 03:42:03 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: by mailman.nyi.freebsd.org (Postfix) id 7A5203F09C8; Mon, 14 Sep 2020 03:42:03 +0000 (UTC) Delivered-To: usb@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 7A04E3F093A for ; Mon, 14 Sep 2020 03:42:03 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4BqXGz2j32z47Jp for ; Mon, 14 Sep 2020 03:42:03 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2610:1c1:1:606c::50:1d]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 4040311088 for ; Mon, 14 Sep 2020 03:42:03 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org ([127.0.1.5]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id 08E3g379060006 for ; Mon, 14 Sep 2020 03:42:03 GMT (envelope-from bugzilla-noreply@freebsd.org) Received: (from www@localhost) by kenobi.freebsd.org (8.15.2/8.15.2/Submit) id 08E3g3Px059990 for usb@FreeBSD.org; Mon, 14 Sep 2020 03:42:03 GMT (envelope-from bugzilla-noreply@freebsd.org) X-Authentication-Warning: kenobi.freebsd.org: www set sender to bugzilla-noreply@freebsd.org using -f From: bugzilla-noreply@freebsd.org To: usb@FreeBSD.org Subject: [Bug 237666] repeated messages of "uhub_reattach_port: giving up port reset - device vanished" Date: Mon, 14 Sep 2020 03:41:59 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: usb X-Bugzilla-Version: 12.1-STABLE X-Bugzilla-Keywords: needs-qa, regression X-Bugzilla-Severity: Affects Some People X-Bugzilla-Who: marklmi26-fbsd@yahoo.com X-Bugzilla-Status: Open X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: usb@FreeBSD.org X-Bugzilla-Flags: mfc-stable12? mfc-stable11- X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: freebsd-usb@freebsd.org X-Mailman-Version: 2.1.33 Precedence: list List-Id: FreeBSD support for USB List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 14 Sep 2020 03:42:03 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D237666 --- Comment #128 from Mark Millard --- (In reply to bawdyanarchist@disroot.org from comment #127) I'm not sure how your speculation would fit with Cortex-A72 vs. Cortex-A53 making a difference in my context. One area where A72 vs. A53 might have a relevant difference is: Cortex-A72 has speculative execution Cortex-A53 does not have speculative execution The Cortex-A72 needs to have some types cache content explicitly managed in places where speculative execution can have cache consequences visible if not handled correctly. I've seen code patched for what was reported to be such an issue for code that was starting to support A72's. (Not necessarily a FreeBSD context, just general looking around.) It leads me to wonder if something is not being properly forced to be up to date when used. Differing code sequences from tuning for different targets might have differing properties for such at some places in the code. Outside the A72 vs. 53 context, some machines might have similar variations in behavior, leading some to show problems and others not. But, I've still no solid evidence of a specific type of error in any specific place. The above is just an example of speculation on my part. --=20 You are receiving this mail because: You are the assignee for the bug.=