Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756501Ab2HGVEO (ORCPT ); Tue, 7 Aug 2012 17:04:14 -0400 Received: from 8bytes.org ([85.214.48.195]:52547 "EHLO mail.8bytes.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754722Ab2HGVEM (ORCPT ); Tue, 7 Aug 2012 17:04:12 -0400 Date: Tue, 7 Aug 2012 23:04:08 +0200 From: Joerg Roedel To: Seth Forshee Cc: linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, x86@kernel.org, Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Len Brown , Joerg Roedel , Suresh Siddha , Yinghai Lu Subject: Re: [PATCH] irq_remap: disable IRQ remapping if any IOAPIC lacks an IOMMU Message-ID: <20120807210408.GK1917@8bytes.org> References: <20120807201030.GJ1917@8bytes.org> <1344372489-14087-1-git-send-email-seth.forshee@canonical.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1344372489-14087-1-git-send-email-seth.forshee@canonical.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-DSPAM-Result: Whitelisted X-DSPAM-Processed: Tue Aug 7 23:04:10 2012 X-DSPAM-Confidence: 0.9995 X-DSPAM-Probability: 0.0000 X-DSPAM-Signature: 502182ca20421372317312 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1855 Lines: 53 On Tue, Aug 07, 2012 at 03:48:09PM -0500, Seth Forshee wrote: > The ACPI tables in the Macbook Air 5,1 define a single IOAPIC with id 2, > but the only remapping unit described in the DMAR table matches id 0. > Interrupt remapping fails as a result, and the kernel panics with the > message "timer doesn't work through Interrupt-remapped IO-APIC." > > To fix this, check each IOAPIC for a corresponding IOMMU. If an IOMMU is > not found, do not allow IRQ remapping to be enabled. > > Signed-off-by: Seth Forshee > --- > drivers/iommu/intel_irq_remapping.c | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > diff --git a/drivers/iommu/intel_irq_remapping.c b/drivers/iommu/intel_irq_remapping.c > index e0b18f3..ce2c0c6 100644 > --- a/drivers/iommu/intel_irq_remapping.c > +++ b/drivers/iommu/intel_irq_remapping.c > @@ -526,6 +526,7 @@ static int __init intel_irq_remapping_supported(void) > static int __init intel_enable_irq_remapping(void) > { > struct dmar_drhd_unit *drhd; > + int ioapic_idx; > int setup = 0; > int eim = 0; > > @@ -534,6 +535,16 @@ static int __init intel_enable_irq_remapping(void) > return -1; > } > > + for (ioapic_idx = 0; ioapic_idx < nr_ioapics; ioapic_idx++) { > + int ioapic_id = mpc_ioapic_id(ioapic_idx); > + if (!map_ioapic_to_ir(ioapic_id)) { > + pr_info("ioapic %d has no mapping iommu, " > + "interrupt remapping will be disabled\n", > + ioapic_id); > + return -1; > + } > + } > + I would change this to pr_err() and add FW_BUG to make clear that this is an error caused by a firmware bug. Joerg -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/