From aa6d1614c069496bab3f6fa5d374c727fa352742 Mon Sep 17 00:00:00 2001

From: Iain Lane <iainl@gnome.org>

Date: Mon, 13 Aug 2018 10:22:22 +0000

Subject: [PATCH 2/2] monitor-manager-kms: Check if GPUs can have outputs

We need a way for mutter to exit if no available GPUs are going to work.

For example if gdm starts gnome-shell and we're using a DRM driver that

doesn't work with KMS then we should exit so that GDM can try with Xorg,

rather than operating in headless mode.

Related: https://gitlab.gnome.org/GNOME/mutter/issues/223

(cherry picked from commit deb541ef5ac2cc07d0259c259bff8d1523388d47)

---

 src/backends/native/meta-gpu-kms.c            |  8 ++++++++

 src/backends/native/meta-gpu-kms.h            |  2 ++

 .../native/meta-monitor-manager-kms.c         | 20 +++++++++++++++++++

 3 files changed, 30 insertions(+)

diff --git a/src/backends/native/meta-gpu-kms.c b/src/backends/native/meta-gpu-kms.c

index 7e7607c46..08c1e7dbe 100644

--- a/src/backends/native/meta-gpu-kms.c

+++ b/src/backends/native/meta-gpu-kms.c

@@ -797,6 +797,12 @@ meta_gpu_kms_read_current (MetaGpu  *gpu,

   return TRUE;

 }

+gboolean

+meta_gpu_kms_can_have_outputs (MetaGpuKms *gpu_kms)

+{

+  return gpu_kms->n_connectors > 0;

+}

+

 MetaGpuKms *

 meta_gpu_kms_new (MetaMonitorManagerKms  *monitor_manager_kms,

                   const char             *kms_file_path,

@@ -860,6 +866,8 @@ meta_gpu_kms_new (MetaMonitorManagerKms  *monitor_manager_kms,

   drmSetClientCap (gpu_kms->fd, DRM_CLIENT_CAP_UNIVERSAL_PLANES, 1);

+  meta_gpu_kms_read_current (META_GPU (gpu_kms), NULL);

+

   source = g_source_new (&kms_event_funcs, sizeof (MetaKmsSource));

   kms_source = (MetaKmsSource *) source;

   kms_source->fd_tag = g_source_add_unix_fd (source,

diff --git a/src/backends/native/meta-gpu-kms.h b/src/backends/native/meta-gpu-kms.h

index 3d0f5f65e..d53ed98c8 100644

--- a/src/backends/native/meta-gpu-kms.h

+++ b/src/backends/native/meta-gpu-kms.h

@@ -59,6 +59,8 @@ gboolean meta_gpu_kms_apply_crtc_mode (MetaGpuKms *gpu_kms,

                                        int         y,

                                        uint32_t    fb_id);

+gboolean meta_gpu_kms_can_have_outputs (MetaGpuKms *gpu_kms);

+

 gboolean meta_gpu_kms_is_crtc_active (MetaGpuKms *gpu_kms,

                                       MetaCrtc   *crtc);

diff --git a/src/backends/native/meta-monitor-manager-kms.c b/src/backends/native/meta-monitor-manager-kms.c

index d8e7b848d..438069110 100644

--- a/src/backends/native/meta-monitor-manager-kms.c

+++ b/src/backends/native/meta-monitor-manager-kms.c

@@ -642,10 +642,12 @@ meta_monitor_manager_kms_initable_init (GInitable    *initable,

                                         GError      **error)

 {

   MetaMonitorManagerKms *manager_kms = META_MONITOR_MANAGER_KMS (initable);

+  MetaMonitorManager *manager = META_MONITOR_MANAGER (manager_kms);

   const char *subsystems[2] = { "drm", NULL };

   GList *gpu_paths;

   g_autofree char *primary_gpu_path = NULL;

   GList *l;

+  gboolean can_have_outputs;

   manager_kms->udev = g_udev_client_new (subsystems);

@@ -694,6 +696,24 @@ meta_monitor_manager_kms_initable_init (GInitable    *initable,

     }

   g_list_free_full (gpu_paths, g_free);

+  can_have_outputs = FALSE;

+  for (l = meta_monitor_manager_get_gpus (manager); l; l = l->next)

+    {

+      MetaGpuKms *gpu_kms = l->data;

+

+      if (meta_gpu_kms_can_have_outputs (gpu_kms))

+        {

+          can_have_outputs = TRUE;

+          break;

+        }

+    }

+  if (!can_have_outputs)

+    {

+      g_set_error (error, G_IO_ERROR, G_IO_ERROR_NOT_FOUND,

+                   "No GPUs with outputs found");

+      return FALSE;

+    }

+

   return TRUE;

 }

-- 

2.19.0