From owner-freebsd-usb@FreeBSD.ORG Thu May 14 16:35:11 2015 Return-Path: Delivered-To: freebsd-usb@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 5099864B for ; Thu, 14 May 2015 16:35:11 +0000 (UTC) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2001:1900:2254:206a::16:76]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 217CC127E for ; Thu, 14 May 2015 16:35:11 +0000 (UTC) Received: from bugs.freebsd.org ([127.0.1.118]) by kenobi.freebsd.org (8.14.9/8.14.9) with ESMTP id t4EGZAtP006026 for ; Thu, 14 May 2015 16:35:11 GMT (envelope-from bugzilla-noreply@freebsd.org) From: bugzilla-noreply@freebsd.org To: freebsd-usb@FreeBSD.org Subject: [Bug 156596] [ehci] Extremely high interrupt rate on ehci/uhci IRQ16 80% cpu utilization on CPU0 Date: Thu, 14 May 2015 16:35:11 +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: 8.2-STABLE X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Only Me X-Bugzilla-Who: sos@DeepCore.dk X-Bugzilla-Status: In Progress X-Bugzilla-Priority: Normal X-Bugzilla-Assigned-To: freebsd-usb@FreeBSD.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: cc 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: 2.1.20 Precedence: list List-Id: FreeBSD support for USB List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 14 May 2015 16:35:11 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D156596 sos@DeepCore.dk changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |sos@DeepCore.dk --- Comment #19 from sos@DeepCore.dk --- Hi All Just stumbled over this one, and the quick solution is to just ignore the interrupt from the (emulated) VGA device, it has nothing todo with USB :) The real problem is that our VGA driver has no idea how to handle the interrupts from the intel built in video HW, so when you yank the VGA cable= the chip wants to signal that event so the system can DTRT(tm). In our case the= re is no ack on that interrupt =3D> instant interrupt storm. My hack just disables the VGA interrupt completely, that might be a bad ide= a if you have anything using it :) However it lets me use my servers with a KVM without problems. Index: vga_pci.c =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D --- vga_pci.c +++ vga_pci.c @@ -125,6 +125,9 @@ if ((config & (PCIM_CMD_PORTEN | PCIM_CMD_MEMEN)) =3D=3D 0) return (0); + /* Disable interrupts */ + pci_write_config(dev, PCIR_COMMAND, config | (1<<10), 2); + /* This video card is the boot display: record its unit number. */ vga_pci_default_unit =3D unit; device_set_flags(dev, 1); -- S=C3=B8ren Schmidt sos@deepcore.dk / sos@freebsd.org "So much code to hack, so little time" --=20 You are receiving this mail because: You are the assignee for the bug.=