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authorJacob Pan <jacob.jun.pan@linux.intel.com>2010-07-16 19:19:22 +0200
committerJesse Barnes <jbarnes@virtuousgeek.org>2010-07-30 18:29:35 +0200
commit253d2e549818f5a4a52e2db0aba3dacee21e5b38 (patch)
tree535ff224cb89860809fa5d948e19e1f3342cf7b3 /drivers/pci/quirks.c
parentPCI: MSI: Remove unsafe and unnecessary hardware access (diff)
downloadlinux-253d2e549818f5a4a52e2db0aba3dacee21e5b38.tar.xz
linux-253d2e549818f5a4a52e2db0aba3dacee21e5b38.zip
PCI: disable mmio during bar sizing
It is a known issue that mmio decoding shall be disabled while doing PCI bar sizing. Host bridge and other devices (PCI PIC) shall be excluded for certain platforms. This patch mainly comes from Mathew Willcox's patch in http://kerneltrap.org/mailarchive/linux-kernel/2007/9/13/258969. A new flag bit "mmio_alway_on" is added to pci_dev with the intention that devices with their mmio decoding cannot be disabled during BAR sizing shall have this bit set, preferrablly in their quirks. Without this patch, Intel Moorestown platform graphics unit will be corrupted during bar sizing activities. Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Diffstat (limited to 'drivers/pci/quirks.c')
-rw-r--r--drivers/pci/quirks.c13
1 files changed, 13 insertions, 0 deletions
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 3a81d9d44019..202efa6f57c4 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -91,6 +91,19 @@ static void __devinit quirk_resource_alignment(struct pci_dev *dev)
}
DECLARE_PCI_FIXUP_HEADER(PCI_ANY_ID, PCI_ANY_ID, quirk_resource_alignment);
+/*
+ * Decoding should be disabled for a PCI device during BAR sizing to avoid
+ * conflict. But doing so may cause problems on host bridge and perhaps other
+ * key system devices. For devices that need to have mmio decoding always-on,
+ * we need to set the dev->mmio_always_on bit.
+ */
+static void __devinit quirk_mmio_always_on(struct pci_dev *dev)
+{
+ if ((dev->class >> 8) == PCI_CLASS_BRIDGE_HOST)
+ dev->mmio_always_on = 1;
+}
+DECLARE_PCI_FIXUP_EARLY(PCI_ANY_ID, PCI_ANY_ID, quirk_mmio_always_on);
+
/* The Mellanox Tavor device gives false positive parity errors
* Mark this device with a broken_parity_status, to allow
* PCI scanning code to "skip" this now blacklisted device.