Date: Thu, 14 May 2015 16:35:11 +0000 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 Message-ID: <bug-156596-17-dLgl2AZnlL@https.bugs.freebsd.org/bugzilla/> In-Reply-To: <bug-156596-17@https.bugs.freebsd.org/bugzilla/> References: <bug-156596-17@https.bugs.freebsd.org/bugzilla/>
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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.=
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