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i195 VGA arbitration patch for 3.16+
diff -rupN linux-3.17.old/drivers/gpu/drm/i915/i915_dma.c linux-3.17/drivers/gpu/drm/i915/i915_dma.c
--- linux-3.17.old/drivers/gpu/drm/i915/i915_dma.c 2014-10-05 17:23:04.000000000 -0200
+++ linux-3.17/drivers/gpu/drm/i915/i915_dma.c 2014-10-08 13:25:35.261920170 -0200
@@ -1316,10 +1316,20 @@ static int i915_load_modeset_init(struct
* If we are a secondary display controller (!PCI_DISPLAY_CLASS_VGA),
* then we do not take part in VGA arbitration and the
* vga_client_register() fails with -ENODEV.
+ *
+ * NB. The set_decode callback here actually only works on GMCH
+ * devices, on newer HD devices we can only disable VGA MMIO space.
+ * Disabling VGA I/O space requires disabling I/O in the PCI command
+ * register. Nonetheless, we like to pretend that we participate in
+ * VGA arbitration and can dynamically disable VGA I/O space because
+ * this makes X happy, even though it's a complete lie.
*/
- ret = vga_client_register(dev->pdev, dev, NULL, i915_vga_set_decode);
- if (ret && ret != -ENODEV)
- goto out;
+ if (!i915.enable_hd_vgaarb || !HAS_PCH_SPLIT(dev)) {
+ ret = vga_client_register(dev->pdev, dev, NULL,
+ i915_vga_set_decode);
+ if (ret && ret != -ENODEV)
+ goto out;
+ }
intel_register_dsm_handler();
@@ -1369,6 +1379,12 @@ static int i915_load_modeset_init(struct
if (ret)
goto cleanup_gem;
+ /*
+ * Must do this after fbcon init so that
+ * vgacon_save_screen() works during the handover.
+ */
+ i915_disable_vga_mem(dev);
+
/* Only enable hotplug handling once the fbdev is fully set up. */
intel_hpd_init(dev);
diff -rupN linux-3.17.old/drivers/gpu/drm/i915/i915_drv.h linux-3.17/drivers/gpu/drm/i915/i915_drv.h
--- linux-3.17.old/drivers/gpu/drm/i915/i915_drv.h 2014-10-05 17:23:04.000000000 -0200
+++ linux-3.17/drivers/gpu/drm/i915/i915_drv.h 2014-10-08 13:26:45.200867353 -0200
@@ -2147,6 +2147,7 @@ struct i915_params {
bool reset;
bool disable_display;
bool disable_vtd_wa;
+ bool enable_hd_vgaarb;
int use_mmio_flip;
bool mmio_debug;
};
diff -rupN linux-3.17.old/drivers/gpu/drm/i915/i915_params.c linux-3.17/drivers/gpu/drm/i915/i915_params.c
--- linux-3.17.old/drivers/gpu/drm/i915/i915_params.c 2014-10-05 17:23:04.000000000 -0200
+++ linux-3.17/drivers/gpu/drm/i915/i915_params.c 2014-10-08 13:28:08.960803683 -0200
@@ -48,6 +48,7 @@ struct i915_params i915 __read_mostly =
.disable_display = 0,
.enable_cmd_parser = 1,
.disable_vtd_wa = 0,
+ .enable_hd_vgaarb = false,
.use_mmio_flip = 0,
.mmio_debug = 0,
};
@@ -159,6 +160,10 @@ module_param_named(enable_cmd_parser, i9
MODULE_PARM_DESC(enable_cmd_parser,
"Enable command parsing (1=enabled [default], 0=disabled)");
+module_param_named(enable_hd_vgaarb, i915.enable_hd_vgaarb, bool, 0444);
+MODULE_PARM_DESC(enable_hd_vgaarb,
+ "Enable support for VGA arbitration on Intel HD IGD. (default: false)");
+
module_param_named(use_mmio_flip, i915.use_mmio_flip, int, 0600);
MODULE_PARM_DESC(use_mmio_flip,
"use MMIO flips (-1=never, 0=driver discretion [default], 1=always)");
diff -rupN linux-3.17.old/drivers/gpu/drm/i915/intel_display.c linux-3.17/drivers/gpu/drm/i915/intel_display.c
--- linux-3.17.old/drivers/gpu/drm/i915/intel_display.c 2014-10-05 17:23:04.000000000 -0200
+++ linux-3.17/drivers/gpu/drm/i915/intel_display.c 2014-10-08 13:25:35.416920053 -0200
@@ -12554,6 +12554,33 @@ static void i915_disable_vga(struct drm_
POSTING_READ(vga_reg);
}
+static void i915_enable_vga_mem(struct drm_device *dev)
+{
+ /* Enable VGA memory on Intel HD */
+ if (i915.enable_hd_vgaarb && HAS_PCH_SPLIT(dev)) {
+ vga_get_uninterruptible(dev->pdev, VGA_RSRC_LEGACY_IO);
+ outb(inb(VGA_MSR_READ) | VGA_MSR_MEM_EN, VGA_MSR_WRITE);
+ vga_set_legacy_decoding(dev->pdev, VGA_RSRC_LEGACY_IO |
+ VGA_RSRC_LEGACY_MEM |
+ VGA_RSRC_NORMAL_IO |
+ VGA_RSRC_NORMAL_MEM);
+ vga_put(dev->pdev, VGA_RSRC_LEGACY_IO);
+ }
+}
+
+void i915_disable_vga_mem(struct drm_device *dev)
+{
+ /* Disable VGA memory on Intel HD */
+ if (i915.enable_hd_vgaarb && HAS_PCH_SPLIT(dev)) {
+ vga_get_uninterruptible(dev->pdev, VGA_RSRC_LEGACY_IO);
+ outb(inb(VGA_MSR_READ) & ~VGA_MSR_MEM_EN, VGA_MSR_WRITE);
+ vga_set_legacy_decoding(dev->pdev, VGA_RSRC_LEGACY_IO |
+ VGA_RSRC_NORMAL_IO |
+ VGA_RSRC_NORMAL_MEM);
+ vga_put(dev->pdev, VGA_RSRC_LEGACY_IO);
+ }
+}
+
void intel_modeset_init_hw(struct drm_device *dev)
{
intel_prepare_ddi(dev);
@@ -12891,6 +12918,7 @@ void i915_redisable_vga_power_on(struct
if (!(I915_READ(vga_reg) & VGA_DISP_DISABLE)) {
DRM_DEBUG_KMS("Something enabled VGA plane, disabling it\n");
i915_disable_vga(dev);
+ i915_disable_vga_mem(dev);
}
}
@@ -13144,6 +13172,8 @@ void intel_modeset_cleanup(struct drm_de
intel_disable_fbc(dev);
+ i915_enable_vga_mem(dev);
+
intel_disable_gt_powersave(dev);
ironlake_teardown_rc6(dev);
diff -rupN linux-3.17.old/drivers/gpu/drm/i915/intel_drv.h linux-3.17/drivers/gpu/drm/i915/intel_drv.h
--- linux-3.17.old/drivers/gpu/drm/i915/intel_drv.h 2014-10-05 17:23:04.000000000 -0200
+++ linux-3.17/drivers/gpu/drm/i915/intel_drv.h 2014-10-08 13:25:35.416920053 -0200
@@ -1102,4 +1102,6 @@ int intel_sprite_get_colorkey(struct drm
/* intel_tv.c */
void intel_tv_init(struct drm_device *dev);
+extern void i915_disable_vga_mem(struct drm_device *dev);
+
#endif /* __INTEL_DRV_H__ */
diff -rupN linux-3.17.old/include/linux/vgaarb.h linux-3.17/include/linux/vgaarb.h
--- linux-3.17.old/include/linux/vgaarb.h 2014-10-05 17:23:04.000000000 -0200
+++ linux-3.17/include/linux/vgaarb.h 2014-10-08 13:25:35.426920046 -0200
@@ -65,8 +65,15 @@ struct pci_dev;
* out of the arbitration process (and can be safe to take
* interrupts at any time.
*/
+#if defined(CONFIG_VGA_ARB)
extern void vga_set_legacy_decoding(struct pci_dev *pdev,
unsigned int decodes);
+#else
+static inline void vga_set_legacy_decoding(struct pci_dev *pdev,
+ unsigned int decodes)
+{
+}
+#endif
/**
* vga_get - acquire & locks VGA resources
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