From owner-svn-src-head@freebsd.org Wed Jun 5 04:58:43 2019 Return-Path: Delivered-To: svn-src-head@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 6011C15C53B3; Wed, 5 Jun 2019 04:58:43 +0000 (UTC) (envelope-from cperciva@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) server-signature RSA-PSS (4096 bits) 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 00B6F6BAD3; Wed, 5 Jun 2019 04:58:43 +0000 (UTC) (envelope-from cperciva@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id CD68414F; Wed, 5 Jun 2019 04:58:42 +0000 (UTC) (envelope-from cperciva@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id x554wgfD059125; Wed, 5 Jun 2019 04:58:42 GMT (envelope-from cperciva@FreeBSD.org) Received: (from cperciva@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id x554wggM059124; Wed, 5 Jun 2019 04:58:42 GMT (envelope-from cperciva@FreeBSD.org) Message-Id: <201906050458.x554wggM059124@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: cperciva set sender to cperciva@FreeBSD.org using -f From: Colin Percival Date: Wed, 5 Jun 2019 04:58:42 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r348681 - head/sys/dev/pci X-SVN-Group: head X-SVN-Commit-Author: cperciva X-SVN-Commit-Paths: head/sys/dev/pci X-SVN-Commit-Revision: 348681 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: 00B6F6BAD3 X-Spamd-Bar: -- Authentication-Results: mx1.freebsd.org X-Spamd-Result: default: False [-2.97 / 15.00]; local_wl_from(0.00)[FreeBSD.org]; NEURAL_HAM_MEDIUM(-1.00)[-1.000,0]; NEURAL_HAM_SHORT(-0.97)[-0.967,0]; ASN(0.00)[asn:11403, ipnet:2610:1c1:1::/48, country:US]; NEURAL_HAM_LONG(-1.00)[-1.000,0] X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 05 Jun 2019 04:58:43 -0000 Author: cperciva Date: Wed Jun 5 04:58:42 2019 New Revision: 348681 URL: https://svnweb.freebsd.org/changeset/base/348681 Log: Only respond to the PCIe Attention Button if a device is already plugged in. Prior to this commit, if PCIEM_SLOT_STA_ABP and PCIEM_SLOT_STA_PDC are asserted simultaneously, FreeBSD sets a 5 second "hardware going away" timer and then processes the "presence detect" change. In the (physically challenging) case that someone presses the "attention button" and inserts a new PCIe device at exactly the same moment, this results in FreeBSD recognizing that the device is present, attaching it, and then detaching it 5 seconds later. On EC2 "bare metal" hardware this is the precise sequence of events which takes place when a new EBS volume is attached; virtual machines have no difficulty effecting physically implausible simultaneity. This patch changes the handling of PCIEM_SLOT_STA_ABP to only detach a device if the presence of a device was detected *before* the interrupt which reports the Attention Button push. Reported by: Matt Wilson Reviewed by: jhb MFC after: 1 week Sponsored by: https://www.patreon.com/cperciva Differential Revision: https://reviews.freebsd.org/D20499 Modified: head/sys/dev/pci/pci_pci.c Modified: head/sys/dev/pci/pci_pci.c ============================================================================== --- head/sys/dev/pci/pci_pci.c Wed Jun 5 04:01:31 2019 (r348680) +++ head/sys/dev/pci/pci_pci.c Wed Jun 5 04:58:42 2019 (r348681) @@ -1170,9 +1170,11 @@ pcib_pcie_intr_hotplug(void *arg) { struct pcib_softc *sc; device_t dev; + uint16_t old_slot_sta; sc = arg; dev = sc->dev; + old_slot_sta = sc->pcie_slot_sta; sc->pcie_slot_sta = pcie_read_config(dev, PCIER_SLOT_STA, 2); /* Clear the events just reported. */ @@ -1188,7 +1190,8 @@ pcib_pcie_intr_hotplug(void *arg) "Attention Button Pressed: Detach Cancelled\n"); sc->flags &= ~PCIB_DETACH_PENDING; callout_stop(&sc->pcie_ab_timer); - } else { + } else if (old_slot_sta & PCIEM_SLOT_STA_PDS) { + /* Only initiate detach sequence if device present. */ device_printf(dev, "Attention Button Pressed: Detaching in 5 seconds\n"); sc->flags |= PCIB_DETACH_PENDING;