1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
|
From 905f94b3533a3e008ca534e2f0d0a01162beb96c Mon Sep 17 00:00:00 2001
From: xiota <>
Date: Mon, 18 Aug 2025 15:44:08 +0000
Subject: [PATCH] i915-vga-arbiter
---
.../drm/i915/display/intel_display_driver.c | 18 ++++++++--
.../drm/i915/display/intel_display_driver.h | 1 +
.../drm/i915/display/intel_display_params.c | 3 ++
.../drm/i915/display/intel_display_params.h | 1 +
drivers/gpu/drm/i915/display/intel_vga.c | 33 +++++++++++++++++++
drivers/gpu/drm/i915/display/intel_vga.h | 4 +++
.../gpu/drm/xe/compat-i915-headers/i915_drv.h | 6 ++++
7 files changed, 63 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_display_driver.c b/drivers/gpu/drm/i915/display/intel_display_driver.c
index 411fe7b9..25f98fb9 100644
--- a/drivers/gpu/drm/i915/display/intel_display_driver.c
+++ b/drivers/gpu/drm/i915/display/intel_display_driver.c
@@ -30,6 +30,7 @@
#include "intel_display_debugfs.h"
#include "intel_display_driver.h"
#include "intel_display_irq.h"
+#include "intel_display_params.h"
#include "intel_display_power.h"
#include "intel_display_types.h"
#include "intel_display_wa.h"
@@ -223,9 +224,11 @@ int intel_display_driver_probe_noirq(struct intel_display *display)
intel_bios_init(display);
- ret = intel_vga_register(display);
- if (ret)
- goto cleanup_bios;
+ if (!display->params.enable_hd_vgaarb || !HAS_PCH_SPLIT(i915)) {
+ ret = intel_vga_register(display);
+ if (ret)
+ goto cleanup_bios;
+ }
intel_psr_dc5_dc6_wa_init(display);
@@ -538,6 +541,12 @@ int intel_display_driver_probe(struct intel_display *display)
intel_overlay_setup(display);
+ /*
+ * Must do this after fbcon init so that
+ * vgacon_save_screen() works during the handover.
+ */
+ intel_vga_disable_mem(display);
+
/* Only enable hotplug handling once the fbdev is fully set up. */
intel_hpd_init(display);
@@ -588,6 +597,8 @@ void intel_display_driver_remove(struct intel_display *display)
if (!HAS_DISPLAY(display))
return;
+ intel_vga_enable_mem(display);
+
flush_workqueue(display->wq.flip);
flush_workqueue(display->wq.modeset);
flush_workqueue(display->wq.cleanup);
@@ -619,6 +630,7 @@ void intel_display_driver_remove_noirq(struct intel_display *display)
intel_unregister_dsm_handler();
/* flush any delayed tasks or pending work */
+ intel_vga_enable_mem(display);
flush_workqueue(i915->unordered_wq);
intel_hdcp_component_fini(display);
diff --git a/drivers/gpu/drm/i915/display/intel_display_driver.h b/drivers/gpu/drm/i915/display/intel_display_driver.h
index 2966ff91..ca0dc757 100644
--- a/drivers/gpu/drm/i915/display/intel_display_driver.h
+++ b/drivers/gpu/drm/i915/display/intel_display_driver.h
@@ -13,6 +13,7 @@ struct drm_modeset_acquire_ctx;
struct intel_display;
struct pci_dev;
+extern void intel_vga_disable_mem(struct intel_display *display);
bool intel_display_driver_probe_defer(struct pci_dev *pdev);
void intel_display_driver_init_hw(struct intel_display *display);
void intel_display_driver_early_probe(struct intel_display *display);
diff --git a/drivers/gpu/drm/i915/display/intel_display_params.c b/drivers/gpu/drm/i915/display/intel_display_params.c
index c4f1ab43..9146bddf 100644
--- a/drivers/gpu/drm/i915/display/intel_display_params.c
+++ b/drivers/gpu/drm/i915/display/intel_display_params.c
@@ -99,6 +99,9 @@ intel_display_param_named_unsafe(force_reset_modeset_test, bool, 0400,
intel_display_param_named(disable_display, bool, 0400,
"Disable display (default: false)");
+intel_display_param_named(enable_hd_vgaarb, bool, 0400,
+ "Enable support for VGA arbitration on Intel HD IGD. (default: false)");
+
intel_display_param_named(verbose_state_checks, bool, 0400,
"Enable verbose logs (ie. WARN_ON()) in case of unexpected hw state conditions.");
diff --git a/drivers/gpu/drm/i915/display/intel_display_params.h b/drivers/gpu/drm/i915/display/intel_display_params.h
index 5317138e..5451b18b 100644
--- a/drivers/gpu/drm/i915/display/intel_display_params.h
+++ b/drivers/gpu/drm/i915/display/intel_display_params.h
@@ -40,6 +40,7 @@ struct drm_printer;
param(bool, load_detect_test, false, 0600) \
param(bool, force_reset_modeset_test, false, 0600) \
param(bool, disable_display, false, 0400) \
+ param(bool, enable_hd_vgaarb, false, 0600) \
param(bool, verbose_state_checks, true, 0400) \
param(bool, nuclear_pageflip, false, 0400) \
param(bool, enable_dp_mst, true, 0600) \
diff --git a/drivers/gpu/drm/i915/display/intel_vga.c b/drivers/gpu/drm/i915/display/intel_vga.c
index 05d140c8..4bb5bc98 100644
--- a/drivers/gpu/drm/i915/display/intel_vga.c
+++ b/drivers/gpu/drm/i915/display/intel_vga.c
@@ -13,9 +13,11 @@
#include "soc/intel_gmch.h"
+#include "i915_drv.h"
#include "i915_reg.h"
#include "intel_de.h"
#include "intel_display.h"
+#include "intel_display_params.h"
#include "intel_vga.h"
#include "intel_vga_regs.h"
@@ -77,6 +79,37 @@ void intel_vga_disable(struct intel_display *display)
intel_de_posting_read(display, vga_reg);
}
+void intel_vga_enable_mem(struct intel_display *display)
+{
+ struct pci_dev *pdev = to_pci_dev(display->drm->dev);
+ struct drm_i915_private *i915 = pdev_to_i915(pdev);
+ /* Enable VGA memory on Intel HD */
+ if (display->params.enable_hd_vgaarb && HAS_PCH_SPLIT(i915)) {
+ vga_get_uninterruptible(pdev, VGA_RSRC_LEGACY_IO);
+ outb(inb(VGA_MIS_R) | (1 << 1), VGA_MIS_W);
+ vga_set_legacy_decoding(pdev, VGA_RSRC_LEGACY_IO |
+ VGA_RSRC_LEGACY_MEM |
+ VGA_RSRC_NORMAL_IO |
+ VGA_RSRC_NORMAL_MEM);
+ vga_put(pdev, VGA_RSRC_LEGACY_IO);
+ }
+}
+
+void intel_vga_disable_mem(struct intel_display *display)
+{
+ struct pci_dev *pdev = to_pci_dev(display->drm->dev);
+ struct drm_i915_private *i915 = pdev_to_i915(pdev);
+ /* Disable VGA memory on Intel HD */
+ if (display->params.enable_hd_vgaarb && HAS_PCH_SPLIT(i915)) {
+ vga_get_uninterruptible(pdev, VGA_RSRC_LEGACY_IO);
+ outb(inb(VGA_MIS_R) & ~(1 << 1), VGA_MIS_W);
+ vga_set_legacy_decoding(pdev, VGA_RSRC_LEGACY_IO |
+ VGA_RSRC_NORMAL_IO |
+ VGA_RSRC_NORMAL_MEM);
+ vga_put(pdev, VGA_RSRC_LEGACY_IO);
+ }
+}
+
void intel_vga_reset_io_mem(struct intel_display *display)
{
struct pci_dev *pdev = to_pci_dev(display->drm->dev);
diff --git a/drivers/gpu/drm/i915/display/intel_vga.h b/drivers/gpu/drm/i915/display/intel_vga.h
index 16d699f3..d91a6cf6 100644
--- a/drivers/gpu/drm/i915/display/intel_vga.h
+++ b/drivers/gpu/drm/i915/display/intel_vga.h
@@ -13,4 +13,8 @@ void intel_vga_disable(struct intel_display *display);
int intel_vga_register(struct intel_display *display);
void intel_vga_unregister(struct intel_display *display);
+/* i915 vga arb patch */
+void intel_vga_enable_mem(struct intel_display *display);
+void intel_vga_disable_mem(struct intel_display *display);
+
#endif /* __INTEL_VGA_H__ */
diff --git a/drivers/gpu/drm/xe/compat-i915-headers/i915_drv.h b/drivers/gpu/drm/xe/compat-i915-headers/i915_drv.h
index 9b7572e0..043734cf 100644
--- a/drivers/gpu/drm/xe/compat-i915-headers/i915_drv.h
+++ b/drivers/gpu/drm/xe/compat-i915-headers/i915_drv.h
@@ -21,6 +21,12 @@ static inline struct drm_i915_private *to_i915(const struct drm_device *dev)
return container_of(dev, struct drm_i915_private, drm);
}
+static inline struct drm_i915_private *pdev_to_i915(struct pci_dev *pdev)
+{
+ struct drm_device *drm = pci_get_drvdata(pdev);
+ return drm ? to_i915(drm) : NULL;
+}
+
/* compat platform checks only for soc/ usage */
#define IS_PLATFORM(xe, x) ((xe)->info.platform == x)
#define IS_I915G(dev_priv) (dev_priv && 0)
--
2.50.1
|