qubes-linux-kernel/patches.arch/x86-mcp51-no-dac

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From: Tejun Heo <tj@kernel.org>
Subject: x86: disallow DAC for MCP51 PCI bridge
References: bnc#463829
Patch-mainline: not yet
MCP51 corrupts DAC transfers. Disallow it. Reported by pgnet on
bnc#463829.
https://bugzilla.novell.com/show_bug.cgi?id=463829
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: pgnet <pgnet.trash@gmail.com>
Signed-off-by: Tejun Heo <teheo@suse.de>
---
arch/x86/kernel/pci-dma.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)
--- a/arch/x86/kernel/pci-dma.c
+++ b/arch/x86/kernel/pci-dma.c
2011-04-19 20:09:59 +00:00
@@ -322,4 +322,18 @@ static __devinit void via_no_dac(struct
}
}
DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_VIA, PCI_ANY_ID, via_no_dac);
+
+/*
+ * MCP51 PCI bridge corrupts data for DAC. Disable it. Reported in
+ * bnc#463829.
+ */
+static __devinit void mcp51_no_dac(struct pci_dev *dev)
+{
+ if (forbid_dac == 0) {
+ printk(KERN_INFO
+ "PCI: MCP51 PCI bridge detected. Disabling DAC.\n");
+ forbid_dac = 1;
+ }
+}
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_NVIDIA, 0x026f, mcp51_no_dac);
#endif