Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755955AbbBQCwH (ORCPT ); Mon, 16 Feb 2015 21:52:07 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:33613 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751723AbbBQBuz (ORCPT ); Mon, 16 Feb 2015 20:50:55 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Matthew Wilcox" , "Myron Stowe" , "William Unruh" , "Martin Lucina" , "Bjorn Helgaas" Date: Tue, 17 Feb 2015 01:46:53 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 015/152] PCI: Restore detection of read-only BARs In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.249 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2660 Lines: 68 3.2.67-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Myron Stowe commit 36e8164882ca6d3c41cb91e6f09a3ed236841f80 upstream. Commit 6ac665c63dca ("PCI: rewrite PCI BAR reading code") masked off low-order bits from 'l', but not from 'sz'. Both are passed to pci_size(), which compares 'base == maxbase' to check for read-only BARs. The masking of 'l' means that comparison will never be 'true', so the check for read-only BARs no longer works. Resolve this by also masking off the low-order bits of 'sz' before passing it into pci_size() as 'maxbase'. With this change, pci_size() will once again catch the problems that have been encountered to date: - AGP aperture BAR of AMD-7xx host bridges: if the AGP window is disabled, this BAR is read-only and read as 0x00000008 [1] - BARs 0-4 of ALi IDE controllers can be non-zero and read-only [1] - Intel Sandy Bridge - Thermal Management Controller [8086:0103]; BAR 0 returning 0xfed98004 [2] - Intel Xeon E5 v3/Core i7 Power Control Unit [8086:2fc0]; Bar 0 returning 0x00001a [3] Link: [1] https://git.kernel.org/cgit/linux/kernel/git/tglx/history.git/commit/drivers/pci/probe.c?id=1307ef6621991f1c4bc3cec1b5a4ebd6fd3d66b9 ("PCI: probing read-only BARs" (pre-git)) Link: [2] https://bugzilla.kernel.org/show_bug.cgi?id=43331 Link: [3] https://bugzilla.kernel.org/show_bug.cgi?id=85991 Reported-by: William Unruh Reported-by: Martin Lucina Signed-off-by: Myron Stowe Signed-off-by: Bjorn Helgaas CC: Matthew Wilcox Signed-off-by: Ben Hutchings --- drivers/pci/probe.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -175,14 +175,17 @@ int __pci_read_base(struct pci_dev *dev, res->flags |= IORESOURCE_SIZEALIGN; if (res->flags & IORESOURCE_IO) { l &= PCI_BASE_ADDRESS_IO_MASK; + sz &= PCI_BASE_ADDRESS_IO_MASK; mask = PCI_BASE_ADDRESS_IO_MASK & (u32) IO_SPACE_LIMIT; } else { l &= PCI_BASE_ADDRESS_MEM_MASK; + sz &= PCI_BASE_ADDRESS_MEM_MASK; mask = (u32)PCI_BASE_ADDRESS_MEM_MASK; } } else { res->flags |= (l & IORESOURCE_ROM_ENABLE); l &= PCI_ROM_ADDRESS_MASK; + sz &= PCI_ROM_ADDRESS_MASK; mask = (u32)PCI_ROM_ADDRESS_MASK; } -- 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/