76 lines
2.8 KiB
Diff
76 lines
2.8 KiB
Diff
From 602e1f209dd983e40d989e871cd253e8187899b8 Mon Sep 17 00:00:00 2001
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From: drago01 <drago01@gmail.com>
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Date: Wed, 26 Oct 2011 13:37:27 -0400
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Subject: [PATCH] Default to igfx_off
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This option seems to causes way to many issues, it is
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being investigated by Intel's chipset team for months now and
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we still don't have any outcome.
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The results so far are "black screen when starting X",
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"system hangs when using GL", "system does not resume".
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The patch adds an intel_iommu=igfx_on option, which makes it opt in,
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rather than opt out.
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Signed-off-by: Adel Gadllah <adel.gadllah@gmail.com>
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Reviewed-by: Adam Jackson <ajax@redhat.com>
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---
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Documentation/kernel-parameters.txt | 11 +++++------
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drivers/iommu/intel-iommu.c | 9 +++++----
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2 files changed, 10 insertions(+), 10 deletions(-)
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diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
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index 81c287f..ee5693b 100644
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--- a/Documentation/kernel-parameters.txt
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+++ b/Documentation/kernel-parameters.txt
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@@ -1014,12 +1014,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
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Enable intel iommu driver.
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off
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Disable intel iommu driver.
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- igfx_off [Default Off]
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- By default, gfx is mapped as normal device. If a gfx
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- device has a dedicated DMAR unit, the DMAR unit is
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- bypassed by not enabling DMAR with this option. In
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- this case, gfx device will use physical address for
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- DMA.
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+ igfx_on [Default Off]
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+ By default, the gfx's DMAR unit is bypassed by not enabling
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+ DMAR with this option. So the gfx device will use physical
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+ address for DMA. When this option is enabled it the gfx is
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+ mapped as normal device.
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forcedac [x86_64]
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With this option iommu will not optimize to look
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for io virtual address below 32-bit forcing dual
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diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
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index bdc447f..240db6b 100644
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--- a/drivers/iommu/intel-iommu.c
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+++ b/drivers/iommu/intel-iommu.c
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@@ -408,7 +408,8 @@ int dmar_disabled = 1;
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int intel_iommu_enabled = 0;
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EXPORT_SYMBOL_GPL(intel_iommu_enabled);
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-static int dmar_map_gfx = 1;
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+/* disabled by default; causes way too many issues */
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+static int dmar_map_gfx = 0;
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static int dmar_forcedac;
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static int intel_iommu_strict;
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static int intel_iommu_superpage = 1;
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@@ -433,10 +434,10 @@ static int __init intel_iommu_setup(char *str)
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} else if (!strncmp(str, "off", 3)) {
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dmar_disabled = 1;
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printk(KERN_INFO "Intel-IOMMU: disabled\n");
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- } else if (!strncmp(str, "igfx_off", 8)) {
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- dmar_map_gfx = 0;
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+ } else if (!strncmp(str, "igfx_on", 7)) {
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+ dmar_map_gfx = 1;
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printk(KERN_INFO
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- "Intel-IOMMU: disable GFX device mapping\n");
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+ "Intel-IOMMU: enabled GFX device mapping\n");
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} else if (!strncmp(str, "forcedac", 8)) {
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printk(KERN_INFO
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"Intel-IOMMU: Forcing DAC for PCI devices\n");
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--
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1.7.7.4
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