[Intel-gfx] [PATCH] RFC hax: drm/i915: Kick out vga console

[Chris Wilson]

Touching the VGA resources on an IVB EFI machine causes hard hangs when
we then kick out the efifb. Ouch.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/i915_dma.c  | 29 +++++++++++++++++++++++++++++
 drivers/video/console/dummycon.c |  1 +
 2 files changed, 30 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index 6de3a43e3acf..837d1a69ca52 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -36,6 +36,8 @@
 #include "i915_drv.h"
 #include "i915_trace.h"
 #include <linux/pci.h>
+#include <linux/console.h>
+#include <linux/vt.h>
 #include <linux/vgaarb.h>
 #include <linux/acpi.h>
 #include <linux/pnp.h>
@@ -1444,6 +1446,27 @@ static int i915_kick_out_firmware_fb(struct drm_i915_private *dev_priv)
 }
 #endif
 
+static int i915_kick_out_vgacon(struct drm_i915_private *dev_priv)
+{
+	int ret;
+
+#if !defined(CONFIG_VGA_CONSOLE)
+	return 0;
+#endif
+
+#if !defined(CONFIG_DUMMY_CONSOLE)
+	return -ENODEV;
+#endif
+
+	DRM_INFO("Replacing VGA console driver\n");
+
+	console_lock();
+	ret = do_take_over_console(&dummy_con, 0, MAX_NR_CONSOLES - 1, 1);
+	console_unlock();
+
+	return ret;
+}
+
 static void i915_dump_device_info(struct drm_i915_private *dev_priv)
 {
 	const struct intel_device_info *info = dev_priv->info;
@@ -1557,6 +1580,12 @@ int i915_driver_load(struct drm_device *dev, unsigned long flags)
 		goto out_regs;
 
 	if (drm_core_check_feature(dev, DRIVER_MODESET)) {
+		ret = i915_kick_out_vgacon(dev_priv);
+		if (ret) {
+			DRM_ERROR("failed to remove conflicting VGA console\n");
+			goto out_gtt;
+		}
+
 		ret = i915_kick_out_firmware_fb(dev_priv);
 		if (ret) {
 			DRM_ERROR("failed to remove conflicting framebuffer drivers\n");
diff --git a/drivers/video/console/dummycon.c b/drivers/video/console/dummycon.c
index b63860f7beab..40bec8d64b0a 100644
--- a/drivers/video/console/dummycon.c
+++ b/drivers/video/console/dummycon.c
@@ -77,3 +77,4 @@ const struct consw dummy_con = {
     .con_set_palette =	DUMMY,
     .con_scrolldelta =	DUMMY,
 };
+EXPORT_SYMBOL_GPL(dummy_con);
-- 
1.8.5.1