[PATCH 5/5] drm/i915: Kick out vga console

Subsystems: console subsystem, drm drivers, framebuffer layer, intel drm i915 driver (meteor lake, dg2 and older excluding poulsbo, moorestown and derivative), the rest

STALE4433d

5 messages, 4 authors, 2014-06-09 · open the first message on its own page

[PATCH 5/5] drm/i915: Kick out vga console

From: Daniel Vetter <hidden>
Date: 2014-06-05 14:59:43 

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

Apparently this also prevents unclaimed register errors on hsw and
hard machine hangs on my i855gm when trying to unbind fbcon.

Also, we want this to make I915_FBDEV=n safe.

v2: Rebase and pimp commit message.

v3: We also need to unregister the vga console, otherwise the unbind
of the fb console before module unload might resurrect it again.

v4: Ignore errors when the vga console is already unregistered - this
can happen when e.g. reloading i915.ko.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?idg813
Cc: David Herrmann <redacted>
Cc: Jean-Christophe Plagniol-Villard <redacted>
Cc: Tomi Valkeinen <redacted>
Cc: linux-fbdev@vger.kernel.org
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Signed-off-by: Chris Wilson <redacted> (v1)
Signed-off-by: Daniel Vetter <redacted>
---
 drivers/gpu/drm/i915/i915_dma.c  | 43 +++++++++++++++++++++++++++++++++++++++-
 drivers/video/console/dummycon.c |  1 +
 drivers/video/console/vgacon.c   |  1 +
 3 files changed, 44 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index 27fe65ac5940..bcb66ddd649e 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>
@@ -1449,6 +1451,38 @@ static void i915_kick_out_firmware_fb(struct drm_i915_private *dev_priv)
 }
 #endif
 
+#if !defined(CONFIG_VGA_CONSOLE)
+static int i915_kick_out_vgacon(struct drm_i915_private *dev_priv)
+{
+	return 0;
+}
+#elif !defined(CONFIG_DUMMY_CONSOLE)
+static int i915_kick_out_vgacon(struct drm_i915_private *dev_priv)
+{
+	return -ENODEV;
+}
+#else
+static int i915_kick_out_vgacon(struct drm_i915_private *dev_priv)
+{
+	int ret;
+
+	DRM_INFO("Replacing VGA console driver\n");
+
+	console_lock();
+	ret = do_take_over_console(&dummy_con, 0, MAX_NR_CONSOLES - 1, 1);
+	if (ret = 0) {
+		ret = do_unregister_con_driver(&vga_con);
+
+		/* Ignore "already unregistered". */
+		if (ret = -ENODEV)
+			ret = 0;
+	}
+	console_unlock();
+
+	return ret;
+}
+#endif
+
 static void i915_dump_device_info(struct drm_i915_private *dev_priv)
 {
 	const struct intel_device_info *info = &dev_priv->info;
@@ -1622,8 +1656,15 @@ int i915_driver_load(struct drm_device *dev, unsigned long flags)
 	if (ret)
 		goto out_regs;
 
-	if (drm_core_check_feature(dev, DRIVER_MODESET))
+	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;
+		}
+
 		i915_kick_out_firmware_fb(dev_priv);
+	}
 
 	pci_set_master(dev->pdev);
 
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);
diff --git a/drivers/video/console/vgacon.c b/drivers/video/console/vgacon.c
index 9d8feac67637..84acd6223dc5 100644
--- a/drivers/video/console/vgacon.c
+++ b/drivers/video/console/vgacon.c
@@ -1440,5 +1440,6 @@ const struct consw vga_con = {
 	.con_build_attr = vgacon_build_attr,
 	.con_invert_region = vgacon_invert_region,
 };
+EXPORT_SYMBOL(vga_con);
 
 MODULE_LICENSE("GPL");
-- 
1.8.1.4

Re: [PATCH 5/5] drm/i915: Kick out vga console

From: David Herrmann <hidden>
Date: 2014-06-06 07:28:08 

Hi

On Thu, Jun 5, 2014 at 4:58 PM, Daniel Vetter [off-list ref] wrote:
quoted hunk
Touching the VGA resources on an IVB EFI machine causes hard hangs when
we then kick out the efifb. Ouch.

Apparently this also prevents unclaimed register errors on hsw and
hard machine hangs on my i855gm when trying to unbind fbcon.

Also, we want this to make I915_FBDEV=n safe.

v2: Rebase and pimp commit message.

v3: We also need to unregister the vga console, otherwise the unbind
of the fb console before module unload might resurrect it again.

v4: Ignore errors when the vga console is already unregistered - this
can happen when e.g. reloading i915.ko.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?idg813
Cc: David Herrmann <redacted>
Cc: Jean-Christophe Plagniol-Villard <redacted>
Cc: Tomi Valkeinen <redacted>
Cc: linux-fbdev@vger.kernel.org
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Signed-off-by: Chris Wilson <redacted> (v1)
Signed-off-by: Daniel Vetter <redacted>
---
 drivers/gpu/drm/i915/i915_dma.c  | 43 +++++++++++++++++++++++++++++++++++++++-
 drivers/video/console/dummycon.c |  1 +
 drivers/video/console/vgacon.c   |  1 +
 3 files changed, 44 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index 27fe65ac5940..bcb66ddd649e 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>
@@ -1449,6 +1451,38 @@ static void i915_kick_out_firmware_fb(struct drm_i915_private *dev_priv)
 }
 #endif

+#if !defined(CONFIG_VGA_CONSOLE)
+static int i915_kick_out_vgacon(struct drm_i915_private *dev_priv)
+{
+       return 0;
+}
+#elif !defined(CONFIG_DUMMY_CONSOLE)
Why not "select DUMMY_CONSOLE if VT"? It's really stupid to disable
DUMMY_CONSOLE.. Furthermore, we already rely on HW_CONSOLE_BINDING so
this should be safe.

Patch looks good to me:

Reviewed-by: David Herrmann <redacted>

Thanks
David
quoted hunk
+static int i915_kick_out_vgacon(struct drm_i915_private *dev_priv)
+{
+       return -ENODEV;
+}
+#else
+static int i915_kick_out_vgacon(struct drm_i915_private *dev_priv)
+{
+       int ret;
+
+       DRM_INFO("Replacing VGA console driver\n");
+
+       console_lock();
+       ret = do_take_over_console(&dummy_con, 0, MAX_NR_CONSOLES - 1, 1);
+       if (ret = 0) {
+               ret = do_unregister_con_driver(&vga_con);
+
+               /* Ignore "already unregistered". */
+               if (ret = -ENODEV)
+                       ret = 0;
+       }
+       console_unlock();
+
+       return ret;
+}
+#endif
+
 static void i915_dump_device_info(struct drm_i915_private *dev_priv)
 {
        const struct intel_device_info *info = &dev_priv->info;
@@ -1622,8 +1656,15 @@ int i915_driver_load(struct drm_device *dev, unsigned long flags)
        if (ret)
                goto out_regs;

-       if (drm_core_check_feature(dev, DRIVER_MODESET))
+       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;
+               }
+
                i915_kick_out_firmware_fb(dev_priv);
+       }

        pci_set_master(dev->pdev);

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);
diff --git a/drivers/video/console/vgacon.c b/drivers/video/console/vgacon.c
index 9d8feac67637..84acd6223dc5 100644
--- a/drivers/video/console/vgacon.c
+++ b/drivers/video/console/vgacon.c
@@ -1440,5 +1440,6 @@ const struct consw vga_con = {
        .con_build_attr = vgacon_build_attr,
        .con_invert_region = vgacon_invert_region,
 };
+EXPORT_SYMBOL(vga_con);

 MODULE_LICENSE("GPL");
--
1.8.1.4

Re: [PATCH 5/5] drm/i915: Kick out vga console

From: Daniel Vetter <hidden>
Date: 2014-06-06 07:48:08 

On Fri, Jun 06, 2014 at 09:28:03AM +0200, David Herrmann wrote:
Hi

On Thu, Jun 5, 2014 at 4:58 PM, Daniel Vetter [off-list ref] wrote:
quoted
Touching the VGA resources on an IVB EFI machine causes hard hangs when
we then kick out the efifb. Ouch.

Apparently this also prevents unclaimed register errors on hsw and
hard machine hangs on my i855gm when trying to unbind fbcon.

Also, we want this to make I915_FBDEV=n safe.

v2: Rebase and pimp commit message.

v3: We also need to unregister the vga console, otherwise the unbind
of the fb console before module unload might resurrect it again.

v4: Ignore errors when the vga console is already unregistered - this
can happen when e.g. reloading i915.ko.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?idg813
Cc: David Herrmann <redacted>
Cc: Jean-Christophe Plagniol-Villard <redacted>
Cc: Tomi Valkeinen <redacted>
Cc: linux-fbdev@vger.kernel.org
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Signed-off-by: Chris Wilson <redacted> (v1)
Signed-off-by: Daniel Vetter <redacted>
---
 drivers/gpu/drm/i915/i915_dma.c  | 43 +++++++++++++++++++++++++++++++++++++++-
 drivers/video/console/dummycon.c |  1 +
 drivers/video/console/vgacon.c   |  1 +
 3 files changed, 44 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index 27fe65ac5940..bcb66ddd649e 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>
@@ -1449,6 +1451,38 @@ static void i915_kick_out_firmware_fb(struct drm_i915_private *dev_priv)
 }
 #endif

+#if !defined(CONFIG_VGA_CONSOLE)
+static int i915_kick_out_vgacon(struct drm_i915_private *dev_priv)
+{
+       return 0;
+}
+#elif !defined(CONFIG_DUMMY_CONSOLE)
Why not "select DUMMY_CONSOLE if VT"? It's really stupid to disable
DUMMY_CONSOLE.. Furthermore, we already rely on HW_CONSOLE_BINDING so
this should be safe.
Iirc this lead kconfig to complain about dep loops ... And I've tried to
figure it out, but I think it's actually impossible. So I let it be with
the -ENODEV to make sure if it's not impossible any more we'll catch it.
-Daniel

Patch looks good to me:

Reviewed-by: David Herrmann <redacted>

Thanks
David
quoted
+static int i915_kick_out_vgacon(struct drm_i915_private *dev_priv)
+{
+       return -ENODEV;
+}
+#else
+static int i915_kick_out_vgacon(struct drm_i915_private *dev_priv)
+{
+       int ret;
+
+       DRM_INFO("Replacing VGA console driver\n");
+
+       console_lock();
+       ret = do_take_over_console(&dummy_con, 0, MAX_NR_CONSOLES - 1, 1);
+       if (ret = 0) {
+               ret = do_unregister_con_driver(&vga_con);
+
+               /* Ignore "already unregistered". */
+               if (ret = -ENODEV)
+                       ret = 0;
+       }
+       console_unlock();
+
+       return ret;
+}
+#endif
+
 static void i915_dump_device_info(struct drm_i915_private *dev_priv)
 {
        const struct intel_device_info *info = &dev_priv->info;
@@ -1622,8 +1656,15 @@ int i915_driver_load(struct drm_device *dev, unsigned long flags)
        if (ret)
                goto out_regs;

-       if (drm_core_check_feature(dev, DRIVER_MODESET))
+       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;
+               }
+
                i915_kick_out_firmware_fb(dev_priv);
+       }

        pci_set_master(dev->pdev);

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);
diff --git a/drivers/video/console/vgacon.c b/drivers/video/console/vgacon.c
index 9d8feac67637..84acd6223dc5 100644
--- a/drivers/video/console/vgacon.c
+++ b/drivers/video/console/vgacon.c
@@ -1440,5 +1440,6 @@ const struct consw vga_con = {
        .con_build_attr = vgacon_build_attr,
        .con_invert_region = vgacon_invert_region,
 };
+EXPORT_SYMBOL(vga_con);

 MODULE_LICENSE("GPL");
--
1.8.1.4
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch

Re: [PATCH 5/5] drm/i915: Kick out vga console

From: Daniel Vetter <hidden>
Date: 2014-06-06 15:20:34 

Tomi/Jean can you please ack merging this through drm-intel trees? It
just exports the vga and dummy consoles so that i915 can do what it
needs to do.

Thanks, Daniel

On Thu, Jun 5, 2014 at 4:58 PM, Daniel Vetter [off-list ref] wrote:
quoted hunk
Touching the VGA resources on an IVB EFI machine causes hard hangs when
we then kick out the efifb. Ouch.

Apparently this also prevents unclaimed register errors on hsw and
hard machine hangs on my i855gm when trying to unbind fbcon.

Also, we want this to make I915_FBDEV=n safe.

v2: Rebase and pimp commit message.

v3: We also need to unregister the vga console, otherwise the unbind
of the fb console before module unload might resurrect it again.

v4: Ignore errors when the vga console is already unregistered - this
can happen when e.g. reloading i915.ko.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?idg813
Cc: David Herrmann <redacted>
Cc: Jean-Christophe Plagniol-Villard <redacted>
Cc: Tomi Valkeinen <redacted>
Cc: linux-fbdev@vger.kernel.org
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Signed-off-by: Chris Wilson <redacted> (v1)
Signed-off-by: Daniel Vetter <redacted>
---
 drivers/gpu/drm/i915/i915_dma.c  | 43 +++++++++++++++++++++++++++++++++++++++-
 drivers/video/console/dummycon.c |  1 +
 drivers/video/console/vgacon.c   |  1 +
 3 files changed, 44 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index 27fe65ac5940..bcb66ddd649e 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>
@@ -1449,6 +1451,38 @@ static void i915_kick_out_firmware_fb(struct drm_i915_private *dev_priv)
 }
 #endif

+#if !defined(CONFIG_VGA_CONSOLE)
+static int i915_kick_out_vgacon(struct drm_i915_private *dev_priv)
+{
+       return 0;
+}
+#elif !defined(CONFIG_DUMMY_CONSOLE)
+static int i915_kick_out_vgacon(struct drm_i915_private *dev_priv)
+{
+       return -ENODEV;
+}
+#else
+static int i915_kick_out_vgacon(struct drm_i915_private *dev_priv)
+{
+       int ret;
+
+       DRM_INFO("Replacing VGA console driver\n");
+
+       console_lock();
+       ret = do_take_over_console(&dummy_con, 0, MAX_NR_CONSOLES - 1, 1);
+       if (ret = 0) {
+               ret = do_unregister_con_driver(&vga_con);
+
+               /* Ignore "already unregistered". */
+               if (ret = -ENODEV)
+                       ret = 0;
+       }
+       console_unlock();
+
+       return ret;
+}
+#endif
+
 static void i915_dump_device_info(struct drm_i915_private *dev_priv)
 {
        const struct intel_device_info *info = &dev_priv->info;
@@ -1622,8 +1656,15 @@ int i915_driver_load(struct drm_device *dev, unsigned long flags)
        if (ret)
                goto out_regs;

-       if (drm_core_check_feature(dev, DRIVER_MODESET))
+       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;
+               }
+
                i915_kick_out_firmware_fb(dev_priv);
+       }

        pci_set_master(dev->pdev);

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);
diff --git a/drivers/video/console/vgacon.c b/drivers/video/console/vgacon.c
index 9d8feac67637..84acd6223dc5 100644
--- a/drivers/video/console/vgacon.c
+++ b/drivers/video/console/vgacon.c
@@ -1440,5 +1440,6 @@ const struct consw vga_con = {
        .con_build_attr = vgacon_build_attr,
        .con_invert_region = vgacon_invert_region,
 };
+EXPORT_SYMBOL(vga_con);

 MODULE_LICENSE("GPL");
--
1.8.1.4


-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch

Re: [PATCH 5/5] drm/i915: Kick out vga console

From: Tomi Valkeinen <hidden>
Date: 2014-06-09 13:23:05 

Hi,

On 06/06/14 18:20, Daniel Vetter wrote:
Tomi/Jean can you please ack merging this through drm-intel trees? It
just exports the vga and dummy consoles so that i915 can do what it
needs to do.
Acked-by: Tomi Valkeinen <redacted>

 Tomi
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