drm/vmwgfx: Fix black screen and device errors when running without fbdev

commit 140bcaa23a1c37b694910424075a15e009120dbe upstream.

When we are running without fbdev, transitioning from the login screen to
X or gnome-shell/wayland will cause a vt switch and the driver will disable
svga mode, losing all modesetting resources. However, the kms atomic state
does not reflect that and may think that a crtc is still turned on, which
will cause device errors when we try to bind an fb to the crtc, and the
screen will remain black.

Fix this by turning off all kms resources before disabling svga mode.

Cc: <stable@vger.kernel.org>
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Sinclair Yeh <syeh@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
index 184340d486c377d38a2f21bb66cc56385a52d37b..86d25f18aa992745e9c4ebb3c89e2bd3199212b9 100644 (file)
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
@@ -1337,6 +1337,19 @@ static void __vmw_svga_disable(struct vmw_private *dev_priv)
  */
 void vmw_svga_disable(struct vmw_private *dev_priv)
 {
+       /*
+        * Disabling SVGA will turn off device modesetting capabilities, so
+        * notify KMS about that so that it doesn't cache atomic state that
+        * isn't valid anymore, for example crtcs turned on.
+        * Strictly we'd want to do this under the SVGA lock (or an SVGA mutex),
+        * but vmw_kms_lost_device() takes the reservation sem and thus we'll
+        * end up with lock order reversal. Thus, a master may actually perform
+        * a new modeset just after we call vmw_kms_lost_device() and race with
+        * vmw_svga_disable(), but that should at worst cause atomic KMS state
+        * to be inconsistent with the device, causing modesetting problems.
+        *
+        */
+       vmw_kms_lost_device(dev_priv->dev);
        ttm_write_lock(&dev_priv->reservation_sem, false);
        spin_lock(&dev_priv->svga_lock);
        if (dev_priv->bdev.man[TTM_PL_VRAM].use_type) {

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
index 7e5f30e234b124aac000c757ae9353db5a17151d..8c65cc3b0dda2d63ffae8629273ef4193ee86dbc 100644 (file)
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
@@ -938,6 +938,7 @@ int vmw_kms_present(struct vmw_private *dev_priv,
 int vmw_kms_update_layout_ioctl(struct drm_device *dev, void *data,
                                struct drm_file *file_priv);
 void vmw_kms_legacy_hotspot_clear(struct vmw_private *dev_priv);
+void vmw_kms_lost_device(struct drm_device *dev);
 
 int vmw_dumb_create(struct drm_file *file_priv,
                    struct drm_device *dev,

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
index 62c2f4be8012be4930d271c64f4aae502ffd8f24..a3d61ead4f01c647676de76d9bf6b1ad54319da4 100644 (file)
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
@@ -2865,3 +2865,14 @@ int vmw_kms_set_config(struct drm_mode_set *set,
 
        return drm_atomic_helper_set_config(set, ctx);
 }
+
+
+/**
+ * vmw_kms_lost_device - Notify kms that modesetting capabilities will be lost
+ *
+ * @dev: Pointer to the drm device
+ */
+void vmw_kms_lost_device(struct drm_device *dev)
+{
+       drm_atomic_helper_shutdown(dev);
+}

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.h b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.h
index cd9da2dd79af1a062d4aaa3d6b6ded468bd4207e..948362c43c733fdd12b02f8a6683785c40b2e9d6 100644 (file)
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.h
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.h
@@ -439,5 +439,4 @@ int vmw_kms_stdu_dma(struct vmw_private *dev_priv,
 
 int vmw_kms_set_config(struct drm_mode_set *set,
                       struct drm_modeset_acquire_ctx *ctx);
-
 #endif