1
0
Fork 0
mutter-performance-source/src/backends/native/meta-kms-device.c
Pekka Paalanen 79491df2b8 kms: Process impl idle callbacks before pre dispatch flush
mode_set_fallback() schedules a call to mode_set_fallback_feedback_idle(), but
it is possible for Mutter to repaint before the idle callbacks are dispatched.
If that happens, mode_set_fallback_feedback_idle() does not get called before
Mutter enters wait_for_pending_flips(), leading to a deadlock.

Add the needed interfaces so that meta_kms_device_dispatch_sync() can flush all
the implementation idle callbacks before it checks if any "events" are
available. This prevents the deadlock by ensuring
mode_set_fallback_feedback_idle() does get called before potentially waiting
for actual DRM events.

Presumably this call would not be needed if the implementation was running in
its own thread, since it would eventually dispatch its idle callbacks before
going to sleep polling on the DRM fd. This call might even be unnecessary
overhead in that case, synchronizing with the implementation thread needlessly.
But the thread does not exist yet, so this is needed for now.

This is part 1 of 2 fixing a complete desktop freeze when drmModePageFlip()
fails with EINVAL and the fallback to drmModeSetCrtc() succeeds but the success
is not registered correctly as completed "flip". The freeze occurs under
wait_for_pending_flips() which calls down into meta_kms_impl_device_dispatch()
which ends up poll()'ing the DRM fd even though drmModeSetCrtc() will not
produce a DRM event, hence the poll() never returns. The freeze was observed
when hotplugging a DisplayLink dock for the first time on Ubuntu 19.10.

CC stable: gnome-3-34

https://gitlab.gnome.org/GNOME/mutter/merge_requests/953
2019-12-06 15:55:35 +00:00

331 lines
8.4 KiB
C

/*
* Copyright (C) 2019 Red Hat
* Copyright (C) 2019 DisplayLink (UK) Ltd.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
* 02111-1307, USA.
*/
#include "config.h"
#include "backends/native/meta-kms-device-private.h"
#include "backends/native/meta-kms-device.h"
#include "backends/native/meta-backend-native.h"
#include "backends/native/meta-kms-impl-device.h"
#include "backends/native/meta-kms-impl.h"
#include "backends/native/meta-kms-plane.h"
#include "backends/native/meta-kms-private.h"
struct _MetaKmsDevice
{
GObject parent;
MetaKms *kms;
MetaKmsImplDevice *impl_device;
MetaKmsDeviceFlag flags;
char *path;
GList *crtcs;
GList *connectors;
GList *planes;
};
G_DEFINE_TYPE (MetaKmsDevice, meta_kms_device, G_TYPE_OBJECT);
MetaKmsImplDevice *
meta_kms_device_get_impl_device (MetaKmsDevice *device)
{
return device->impl_device;
}
int
meta_kms_device_leak_fd (MetaKmsDevice *device)
{
return meta_kms_impl_device_leak_fd (device->impl_device);
}
const char *
meta_kms_device_get_path (MetaKmsDevice *device)
{
return device->path;
}
MetaKmsDeviceFlag
meta_kms_device_get_flags (MetaKmsDevice *device)
{
return device->flags;
}
GList *
meta_kms_device_get_connectors (MetaKmsDevice *device)
{
return device->connectors;
}
GList *
meta_kms_device_get_crtcs (MetaKmsDevice *device)
{
return device->crtcs;
}
static GList *
meta_kms_device_get_planes (MetaKmsDevice *device)
{
return device->planes;
}
MetaKmsPlane *
meta_kms_device_get_primary_plane_for (MetaKmsDevice *device,
MetaKmsCrtc *crtc)
{
GList *l;
for (l = meta_kms_device_get_planes (device); l; l = l->next)
{
MetaKmsPlane *plane = l->data;
if (meta_kms_plane_get_plane_type (plane) != META_KMS_PLANE_TYPE_PRIMARY)
continue;
if (meta_kms_plane_is_usable_with (plane, crtc))
return plane;
}
return NULL;
}
void
meta_kms_device_update_states_in_impl (MetaKmsDevice *device)
{
MetaKmsImplDevice *impl_device = meta_kms_device_get_impl_device (device);
meta_assert_in_kms_impl (device->kms);
meta_assert_is_waiting_for_kms_impl_task (device->kms);
meta_kms_impl_device_update_states (impl_device);
g_list_free (device->crtcs);
device->crtcs = meta_kms_impl_device_copy_crtcs (impl_device);
g_list_free (device->connectors);
device->connectors = meta_kms_impl_device_copy_connectors (impl_device);
g_list_free (device->planes);
device->planes = meta_kms_impl_device_copy_planes (impl_device);
}
void
meta_kms_device_predict_states_in_impl (MetaKmsDevice *device,
MetaKmsUpdate *update)
{
MetaKmsImplDevice *impl_device = meta_kms_device_get_impl_device (device);
meta_assert_in_kms_impl (device->kms);
meta_kms_impl_device_predict_states (impl_device, update);
}
static gboolean
dispatch_in_impl (MetaKmsImpl *impl,
gpointer user_data,
GError **error)
{
MetaKmsImplDevice *impl_device = META_KMS_IMPL_DEVICE (user_data);
return meta_kms_impl_device_dispatch (impl_device, error);
}
static gboolean
dispatch_idle_in_impl (MetaKmsImpl *impl,
gpointer user_data,
GError **error)
{
meta_kms_impl_dispatch_idle (impl);
return TRUE;
}
int
meta_kms_device_dispatch_sync (MetaKmsDevice *device,
GError **error)
{
int callback_count;
if (!meta_kms_run_impl_task_sync (device->kms,
dispatch_idle_in_impl,
device->impl_device,
error))
return -1;
callback_count = meta_kms_flush_callbacks (device->kms);
if (callback_count > 0)
return TRUE;
if (!meta_kms_run_impl_task_sync (device->kms,
dispatch_in_impl,
device->impl_device,
error))
return -1;
return meta_kms_flush_callbacks (device->kms);
}
typedef struct _CreateImplDeviceData
{
MetaKmsDevice *device;
int fd;
MetaKmsImplDevice *out_impl_device;
GList *out_crtcs;
GList *out_connectors;
GList *out_planes;
} CreateImplDeviceData;
static gboolean
create_impl_device_in_impl (MetaKmsImpl *impl,
gpointer user_data,
GError **error)
{
CreateImplDeviceData *data = user_data;
MetaKmsImplDevice *impl_device;
impl_device = meta_kms_impl_device_new (data->device, impl, data->fd, error);
if (!impl_device)
return FALSE;
data->out_impl_device = impl_device;
data->out_crtcs = meta_kms_impl_device_copy_crtcs (impl_device);
data->out_connectors = meta_kms_impl_device_copy_connectors (impl_device);
data->out_planes = meta_kms_impl_device_copy_planes (impl_device);
return TRUE;
}
MetaKmsDevice *
meta_kms_device_new (MetaKms *kms,
const char *path,
MetaKmsDeviceFlag flags,
GError **error)
{
MetaBackend *backend = meta_kms_get_backend (kms);
MetaBackendNative *backend_native = META_BACKEND_NATIVE (backend);
MetaLauncher *launcher = meta_backend_native_get_launcher (backend_native);
MetaKmsDevice *device;
CreateImplDeviceData data;
int fd;
fd = meta_launcher_open_restricted (launcher, path, error);
if (fd == -1)
return NULL;
device = g_object_new (META_TYPE_KMS_DEVICE, NULL);
device->kms = kms;
data = (CreateImplDeviceData) {
.device = device,
.fd = fd,
};
if (!meta_kms_run_impl_task_sync (kms, create_impl_device_in_impl, &data,
error))
{
meta_launcher_close_restricted (launcher, fd);
g_object_unref (device);
return NULL;
}
device->impl_device = data.out_impl_device;
device->flags = flags;
device->path = g_strdup (path);
device->crtcs = data.out_crtcs;
device->connectors = data.out_connectors;
device->planes = data.out_planes;
return device;
}
typedef struct _FreeImplDeviceData
{
MetaKmsImplDevice *impl_device;
int out_fd;
} FreeImplDeviceData;
static gboolean
free_impl_device_in_impl (MetaKmsImpl *impl,
gpointer user_data,
GError **error)
{
FreeImplDeviceData *data = user_data;
MetaKmsImplDevice *impl_device = data->impl_device;
int fd;
fd = meta_kms_impl_device_close (impl_device);
g_object_unref (impl_device);
data->out_fd = fd;
return TRUE;
}
static void
meta_kms_device_finalize (GObject *object)
{
MetaKmsDevice *device = META_KMS_DEVICE (object);
MetaBackend *backend = meta_kms_get_backend (device->kms);
MetaBackendNative *backend_native = META_BACKEND_NATIVE (backend);
MetaLauncher *launcher = meta_backend_native_get_launcher (backend_native);
g_free (device->path);
g_list_free (device->crtcs);
g_list_free (device->connectors);
g_list_free (device->planes);
if (device->impl_device)
{
FreeImplDeviceData data;
GError *error = NULL;
data = (FreeImplDeviceData) {
.impl_device = device->impl_device,
};
if (!meta_kms_run_impl_task_sync (device->kms, free_impl_device_in_impl, &data,
&error))
{
g_warning ("Failed to close KMS impl device: %s", error->message);
g_error_free (error);
}
else
{
meta_launcher_close_restricted (launcher, data.out_fd);
}
}
G_OBJECT_CLASS (meta_kms_device_parent_class)->finalize (object);
}
static void
meta_kms_device_init (MetaKmsDevice *device)
{
}
static void
meta_kms_device_class_init (MetaKmsDeviceClass *klass)
{
GObjectClass *object_class = G_OBJECT_CLASS (klass);
object_class->finalize = meta_kms_device_finalize;
}