/*
 * Copyright (C) 2018-2019 Red Hat
 * Copyright (C) 2019-2020 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-impl-simple.h"

#include <errno.h>
#include <gbm.h>
#include <xf86drmMode.h>

#include "backends/native/meta-kms-connector.h"
#include "backends/native/meta-kms-crtc.h"
#include "backends/native/meta-kms-device-private.h"
#include "backends/native/meta-kms-page-flip-private.h"
#include "backends/native/meta-kms-plane.h"
#include "backends/native/meta-kms-private.h"
#include "backends/native/meta-kms-update-private.h"
#include "backends/native/meta-kms-utils.h"

typedef struct _CachedModeSet
{
  GList *connectors;
  drmModeModeInfo *drm_mode;
} CachedModeSet;

struct _MetaKmsImplSimple
{
  MetaKmsImpl parent;

  GSource *mode_set_fallback_feedback_source;
  GList *mode_set_fallback_page_flip_datas;

  GList *pending_page_flip_retries;
  GSource *retry_page_flips_source;

  GList *postponed_page_flip_datas;
  GList *postponed_mode_set_fallback_datas;

  GHashTable *cached_mode_sets;
};

G_DEFINE_TYPE (MetaKmsImplSimple, meta_kms_impl_simple,
               META_TYPE_KMS_IMPL)

static void
flush_postponed_page_flip_datas (MetaKmsImplSimple *impl_simple);

MetaKmsImplSimple *
meta_kms_impl_simple_new (MetaKms  *kms,
                          GError  **error)
{
  return g_object_new (META_TYPE_KMS_IMPL_SIMPLE,
                       "kms", kms,
                       NULL);
}

static gboolean
process_connector_property (MetaKmsImpl    *impl,
                            MetaKmsUpdate  *update,
                            gpointer        update_entry,
                            GError        **error)
{
  MetaKmsConnectorProperty *connector_property = update_entry;
  MetaKmsConnector *connector = connector_property->connector;
  MetaKmsDevice *device = meta_kms_connector_get_device (connector);
  MetaKmsImplDevice *impl_device = meta_kms_device_get_impl_device (device);
  int fd;
  int ret;

  fd = meta_kms_impl_device_get_fd (impl_device);

  ret = drmModeObjectSetProperty (fd,
                                  meta_kms_connector_get_id (connector),
                                  DRM_MODE_OBJECT_CONNECTOR,
                                  connector_property->prop_id,
                                  connector_property->value);
  if (ret != 0)
    {
      g_set_error (error, G_IO_ERROR, g_io_error_from_errno (-ret),
                   "Failed to set connector %u property %u: %s",
                   meta_kms_connector_get_id (connector),
                   connector_property->prop_id,
                   g_strerror (-ret));
      return FALSE;
    }

  return TRUE;
}

static gboolean
process_plane_property (MetaKmsImpl      *impl,
                        MetaKmsPlane     *plane,
                        MetaKmsProperty  *prop,
                        GError          **error)
{
  MetaKmsDevice *device = meta_kms_plane_get_device (plane);
  MetaKmsImplDevice *impl_device = meta_kms_device_get_impl_device (device);
  int fd;
  int ret;

  fd = meta_kms_impl_device_get_fd (impl_device);

  ret = drmModeObjectSetProperty (fd,
                                  meta_kms_plane_get_id (plane),
                                  DRM_MODE_OBJECT_PLANE,
                                  prop->prop_id,
                                  prop->value);
  if (ret != 0)
    {
      g_set_error (error, G_IO_ERROR, g_io_error_from_errno (-ret),
                   "Failed to set plane %u property %u: %s",
                   meta_kms_plane_get_id (plane),
                   prop->prop_id,
                   g_strerror (-ret));
      return FALSE;
    }

  return TRUE;
}

static CachedModeSet *
cached_mode_set_new (GList                 *connectors,
                     const drmModeModeInfo *drm_mode)
{
  CachedModeSet *cached_mode_set;

  cached_mode_set = g_new0 (CachedModeSet, 1);
  *cached_mode_set = (CachedModeSet) {
    .connectors = g_list_copy (connectors),
    .drm_mode = g_memdup2 (drm_mode, sizeof *drm_mode),
  };

  return cached_mode_set;
}

static void
cached_mode_set_free (CachedModeSet *cached_mode_set)
{
  g_list_free (cached_mode_set->connectors);
  g_free (cached_mode_set->drm_mode);
  g_free (cached_mode_set);
}

static void
fill_connector_ids_array (GList     *connectors,
                          uint32_t **out_connectors,
                          int       *out_n_connectors)
{
  GList *l;
  int i;

  *out_n_connectors = g_list_length (connectors);
  *out_connectors = g_new0 (uint32_t, *out_n_connectors);
  i = 0;
  for (l = connectors; l; l = l->next)
    {
      MetaKmsConnector *connector = l->data;

      (*out_connectors)[i++] = meta_kms_connector_get_id (connector);
    }
}

static gboolean
process_mode_set (MetaKmsImpl     *impl,
                  MetaKmsUpdate   *update,
                  gpointer         update_entry,
                  GError         **error)
{
  MetaKmsModeSet *mode_set = update_entry;
  MetaKmsImplSimple *impl_simple = META_KMS_IMPL_SIMPLE (impl);
  MetaKmsCrtc *crtc = mode_set->crtc;
  MetaKmsDevice *device = meta_kms_crtc_get_device (crtc);
  MetaKmsImplDevice *impl_device = meta_kms_device_get_impl_device (device);
  g_autofree uint32_t *connectors = NULL;
  int n_connectors;
  MetaKmsPlaneAssignment *plane_assignment;
  uint32_t x, y;
  uint32_t fb_id;
  int fd;
  int ret;

  crtc = mode_set->crtc;

  if (mode_set->drm_mode)
    {
      GList *l;

      fill_connector_ids_array (mode_set->connectors,
                                &connectors,
                                &n_connectors);

      plane_assignment = meta_kms_update_get_primary_plane_assignment (update,
                                                                       crtc);
      if (!plane_assignment)
        {
          g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,
                       "Missing primary plane assignment for legacy mode set on CRTC %u",
                       meta_kms_crtc_get_id (crtc));
          return FALSE;
        }

      x = meta_fixed_16_to_int (plane_assignment->src_rect.x);
      y = meta_fixed_16_to_int (plane_assignment->src_rect.y);

      for (l = plane_assignment->plane_properties; l; l = l->next)
        {
          MetaKmsProperty *prop = l->data;

          if (!process_plane_property (impl, plane_assignment->plane,
                                       prop, error))
            return FALSE;
        }

      fb_id = plane_assignment->fb_id;
    }
  else
    {
      x = y = 0;
      n_connectors = 0;
      connectors = NULL;
      fb_id = 0;
    }

  fd = meta_kms_impl_device_get_fd (impl_device);
  ret = drmModeSetCrtc (fd,
                        meta_kms_crtc_get_id (crtc),
                        fb_id,
                        x, y,
                        connectors, n_connectors,
                        mode_set->drm_mode);
  if (ret != 0)
    {
      g_set_error (error, G_IO_ERROR, g_io_error_from_errno (-ret),
                   "Failed to set mode %s on CRTC %u: %s",
                   mode_set->drm_mode ? mode_set->drm_mode->name : "off",
                   meta_kms_crtc_get_id (crtc),
                   g_strerror (-ret));
      return FALSE;
    }

  if (mode_set->drm_mode)
    {
      g_hash_table_replace (impl_simple->cached_mode_sets,
                            crtc,
                            cached_mode_set_new (mode_set->connectors,
                                                 mode_set->drm_mode));
    }
  else
    {
      g_hash_table_remove (impl_simple->cached_mode_sets, crtc);
    }

  return TRUE;
}

static gboolean
process_crtc_gamma (MetaKmsImpl    *impl,
                    MetaKmsUpdate  *update,
                    gpointer        update_entry,
                    GError        **error)
{
  MetaKmsCrtcGamma *gamma = update_entry;
  MetaKmsCrtc *crtc = gamma->crtc;
  MetaKmsDevice *device = meta_kms_crtc_get_device (crtc);
  MetaKmsImplDevice *impl_device = meta_kms_device_get_impl_device (device);
  int fd;
  int ret;

  fd = meta_kms_impl_device_get_fd (impl_device);
  ret = drmModeCrtcSetGamma (fd, meta_kms_crtc_get_id (crtc),
                             gamma->size,
                             gamma->red,
                             gamma->green,
                             gamma->blue);
  if (ret != 0)
    {
      g_set_error (error, G_IO_ERROR, g_io_error_from_errno (-ret),
                   "drmModeCrtcSetGamma on CRTC %u failed: %s",
                   meta_kms_crtc_get_id (crtc),
                   g_strerror (-ret));
      return FALSE;
    }

  return TRUE;
}

static gboolean
is_timestamp_earlier_than (uint64_t ts1,
                           uint64_t ts2)
{
  if (ts1 == ts2)
    return FALSE;
  else
    return ts2 - ts1 < UINT64_MAX / 2;
}

typedef struct _RetryPageFlipData
{
  MetaKmsCrtc *crtc;
  uint32_t fb_id;
  MetaKmsPageFlipData *page_flip_data;
  float refresh_rate;
  uint64_t retry_time_us;
} RetryPageFlipData;

static void
retry_page_flip_data_free (RetryPageFlipData *retry_page_flip_data)
{
  g_assert (!retry_page_flip_data->page_flip_data);
  g_free (retry_page_flip_data);
}

static CachedModeSet *
get_cached_mode_set (MetaKmsImplSimple *impl_simple,
                     MetaKmsCrtc       *crtc)
{
  return g_hash_table_lookup (impl_simple->cached_mode_sets, crtc);
}

static float
get_cached_crtc_refresh_rate (MetaKmsImplSimple *impl_simple,
                              MetaKmsCrtc       *crtc)
{
  CachedModeSet *cached_mode_set;

  cached_mode_set = g_hash_table_lookup (impl_simple->cached_mode_sets,
                                         crtc);
  g_assert (cached_mode_set);

  return meta_calculate_drm_mode_refresh_rate (cached_mode_set->drm_mode);
}

static gboolean
retry_page_flips (gpointer user_data)
{
  MetaKmsImplSimple *impl_simple = META_KMS_IMPL_SIMPLE (user_data);
  uint64_t now_us;
  GList *l;

  meta_assert_in_kms_impl (meta_kms_impl_get_kms (META_KMS_IMPL (impl_simple)));

  now_us = g_source_get_time (impl_simple->retry_page_flips_source);

  l = impl_simple->pending_page_flip_retries;
  while (l)
    {
      RetryPageFlipData *retry_page_flip_data = l->data;
      MetaKmsCrtc *crtc = retry_page_flip_data->crtc;
      MetaKmsDevice *device = meta_kms_crtc_get_device (crtc);
      MetaKmsImplDevice *impl_device = meta_kms_device_get_impl_device (device);
      GList *l_next = l->next;
      int fd;
      int ret;
      MetaKmsPageFlipData *page_flip_data;

      if (is_timestamp_earlier_than (now_us,
                                     retry_page_flip_data->retry_time_us))
        {
          l = l_next;
          continue;
        }

      fd = meta_kms_impl_device_get_fd (impl_device);
      ret = drmModePageFlip (fd,
                             meta_kms_crtc_get_id (crtc),
                             retry_page_flip_data->fb_id,
                             DRM_MODE_PAGE_FLIP_EVENT,
                             retry_page_flip_data->page_flip_data);
      if (ret == -EBUSY)
        {
          float refresh_rate;

          refresh_rate = get_cached_crtc_refresh_rate (impl_simple, crtc);
          retry_page_flip_data->retry_time_us +=
            (uint64_t) (G_USEC_PER_SEC / refresh_rate);
          l = l_next;
          continue;
        }

      impl_simple->pending_page_flip_retries =
        g_list_remove_link (impl_simple->pending_page_flip_retries, l);

      page_flip_data = g_steal_pointer (&retry_page_flip_data->page_flip_data);
      if (ret != 0)
        {
          g_autoptr (GError) error = NULL;

          g_set_error (&error, G_IO_ERROR, g_io_error_from_errno (-ret),
                       "drmModePageFlip on CRTC %u failed: %s",
                       meta_kms_crtc_get_id (crtc),
                       g_strerror (-ret));
          if (!g_error_matches (error,
                                G_IO_ERROR,
                                G_IO_ERROR_PERMISSION_DENIED))
            g_critical ("Failed to page flip: %s", error->message);

          meta_kms_page_flip_data_discard_in_impl (page_flip_data, error);
        }

      retry_page_flip_data_free (retry_page_flip_data);

      l = l_next;
    }

  if (impl_simple->pending_page_flip_retries)
    {
      GList *l;
      uint64_t earliest_retry_time_us = 0;

      for (l = impl_simple->pending_page_flip_retries; l; l = l->next)
        {
          RetryPageFlipData *retry_page_flip_data = l->data;

          if (l == impl_simple->pending_page_flip_retries ||
              is_timestamp_earlier_than (retry_page_flip_data->retry_time_us,
                                         earliest_retry_time_us))
            earliest_retry_time_us = retry_page_flip_data->retry_time_us;
        }

      g_source_set_ready_time (impl_simple->retry_page_flips_source,
                               earliest_retry_time_us);
      return G_SOURCE_CONTINUE;
    }
  else
    {
      g_clear_pointer (&impl_simple->retry_page_flips_source,
                       g_source_unref);

      flush_postponed_page_flip_datas (impl_simple);

      return G_SOURCE_REMOVE;
    }
}

static void
schedule_retry_page_flip (MetaKmsImplSimple   *impl_simple,
                          MetaKmsCrtc         *crtc,
                          uint32_t             fb_id,
                          float                refresh_rate,
                          MetaKmsPageFlipData *page_flip_data)
{
  RetryPageFlipData *retry_page_flip_data;
  uint64_t now_us;
  uint64_t retry_time_us;

  now_us = g_get_monotonic_time ();
  retry_time_us = now_us + (uint64_t) (G_USEC_PER_SEC / refresh_rate);

  retry_page_flip_data = g_new0 (RetryPageFlipData, 1);
  *retry_page_flip_data = (RetryPageFlipData) {
    .crtc = crtc,
    .fb_id = fb_id,
    .page_flip_data = meta_kms_page_flip_data_ref (page_flip_data),
    .refresh_rate = refresh_rate,
    .retry_time_us = retry_time_us,
  };

  if (!impl_simple->retry_page_flips_source)
    {
      MetaKms *kms = meta_kms_impl_get_kms (META_KMS_IMPL (impl_simple));
      GSource *source;

      source = meta_kms_add_source_in_impl (kms, retry_page_flips,
                                            impl_simple, NULL);
      g_source_set_ready_time (source, retry_time_us);

      impl_simple->retry_page_flips_source = source;
    }
  else
    {
      GList *l;

      for (l = impl_simple->pending_page_flip_retries; l; l = l->next)
        {
          RetryPageFlipData *pending_retry_page_flip_data = l->data;
          uint64_t pending_retry_time_us =
            pending_retry_page_flip_data->retry_time_us;

          if (is_timestamp_earlier_than (retry_time_us, pending_retry_time_us))
            {
              g_source_set_ready_time (impl_simple->retry_page_flips_source,
                                       retry_time_us);
              break;
            }
        }
    }

  impl_simple->pending_page_flip_retries =
    g_list_append (impl_simple->pending_page_flip_retries,
                   retry_page_flip_data);
}

static void
invoke_page_flip_datas (GList                        *page_flip_datas,
                        MetaPageFlipDataFeedbackFunc  func)
{
  g_list_foreach (page_flip_datas, (GFunc) func, NULL);
}

static void
clear_page_flip_datas (GList **page_flip_datas)
{
  g_list_free_full (*page_flip_datas,
                    (GDestroyNotify) meta_kms_page_flip_data_unref);
  *page_flip_datas = NULL;
}

static gboolean
mode_set_fallback_feedback_idle (gpointer user_data)
{
  MetaKmsImplSimple *impl_simple = user_data;

  g_clear_pointer (&impl_simple->mode_set_fallback_feedback_source,
                   g_source_unref);

  if (impl_simple->pending_page_flip_retries)
    {
      impl_simple->postponed_mode_set_fallback_datas =
        g_steal_pointer (&impl_simple->mode_set_fallback_page_flip_datas);
    }
  else
    {
      invoke_page_flip_datas (impl_simple->mode_set_fallback_page_flip_datas,
                              meta_kms_page_flip_data_mode_set_fallback_in_impl);
      clear_page_flip_datas (&impl_simple->mode_set_fallback_page_flip_datas);
    }

  return G_SOURCE_REMOVE;
}

static gboolean
mode_set_fallback (MetaKmsImplSimple       *impl_simple,
                   MetaKmsUpdate           *update,
                   MetaKmsPageFlip         *page_flip,
                   MetaKmsPlaneAssignment  *plane_assignment,
                   MetaKmsPageFlipData     *page_flip_data,
                   GError                 **error)
{
  MetaKms *kms = meta_kms_impl_get_kms (META_KMS_IMPL (impl_simple));
  MetaKmsCrtc *crtc = page_flip->crtc;
  MetaKmsDevice *device = meta_kms_crtc_get_device (crtc);
  MetaKmsImplDevice *impl_device = meta_kms_device_get_impl_device (device);
  CachedModeSet *cached_mode_set;
  g_autofree uint32_t *connectors = NULL;
  int n_connectors;
  uint32_t x, y;
  int fd;
  int ret;

  cached_mode_set = g_hash_table_lookup (impl_simple->cached_mode_sets,
                                         crtc);
  if (!cached_mode_set)
    {
      g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,
                   "Missing mode set for page flip fallback");
      return FALSE;
    }

  fill_connector_ids_array (cached_mode_set->connectors,
                            &connectors,
                            &n_connectors);

  x = meta_fixed_16_to_int (plane_assignment->src_rect.x);
  y = meta_fixed_16_to_int (plane_assignment->src_rect.y);

  fd = meta_kms_impl_device_get_fd (impl_device);
  ret = drmModeSetCrtc (fd,
                        meta_kms_crtc_get_id (crtc),
                        plane_assignment->fb_id,
                        x, y,
                        connectors, n_connectors,
                        cached_mode_set->drm_mode);
  if (ret != 0)
    {
      g_set_error (error, G_IO_ERROR, g_io_error_from_errno (-ret),
                   "drmModeSetCrtc mode '%s' on CRTC %u failed: %s",
                   cached_mode_set->drm_mode->name,
                   meta_kms_crtc_get_id (crtc),
                   g_strerror (-ret));
      return FALSE;
    }

  if (!impl_simple->mode_set_fallback_feedback_source)
    {
      GSource *source;

      source = meta_kms_add_source_in_impl (kms,
                                            mode_set_fallback_feedback_idle,
                                            impl_simple,
                                            NULL);
      impl_simple->mode_set_fallback_feedback_source = source;
    }

  impl_simple->mode_set_fallback_page_flip_datas =
    g_list_prepend (impl_simple->mode_set_fallback_page_flip_datas,
                    meta_kms_page_flip_data_ref (page_flip_data));

  return TRUE;
}

static gboolean
process_page_flip (MetaKmsImpl    *impl,
                   MetaKmsUpdate  *update,
                   gpointer        update_entry,
                   GError        **error)
{
  MetaKmsPageFlip *page_flip = update_entry;
  MetaKmsImplSimple *impl_simple = META_KMS_IMPL_SIMPLE (impl);
  MetaKmsCrtc *crtc;
  MetaKmsDevice *device;
  MetaKmsImplDevice *impl_device;
  MetaKmsPlaneAssignment *plane_assignment;
  MetaKmsPageFlipData *page_flip_data;
  MetaKmsCustomPageFlipFunc custom_page_flip_func;
  int fd;
  int ret;

  crtc = page_flip->crtc;
  plane_assignment = meta_kms_update_get_primary_plane_assignment (update,
                                                                   crtc);

  page_flip_data = meta_kms_page_flip_data_new (impl,
                                                crtc,
                                                page_flip->feedback,
                                                page_flip->user_data);

  device = meta_kms_crtc_get_device (crtc);
  impl_device = meta_kms_device_get_impl_device (device);
  fd = meta_kms_impl_device_get_fd (impl_device);
  custom_page_flip_func = page_flip->custom_page_flip_func;
  if (custom_page_flip_func)
    {
      ret = custom_page_flip_func (page_flip->custom_page_flip_user_data,
                                   meta_kms_page_flip_data_ref (page_flip_data));
    }
  else
    {
      ret = drmModePageFlip (fd,
                             meta_kms_crtc_get_id (crtc),
                             plane_assignment->fb_id,
                             DRM_MODE_PAGE_FLIP_EVENT,
                             meta_kms_page_flip_data_ref (page_flip_data));
    }

  if (ret != 0)
    meta_kms_page_flip_data_unref (page_flip_data);

  if (ret == -EBUSY)
    {
      CachedModeSet *cached_mode_set;

      cached_mode_set = get_cached_mode_set (impl_simple, crtc);
      if (cached_mode_set)
        {
          drmModeModeInfo *drm_mode;
          float refresh_rate;

          drm_mode = cached_mode_set->drm_mode;
          refresh_rate = meta_calculate_drm_mode_refresh_rate (drm_mode);
          schedule_retry_page_flip (impl_simple,
                                    crtc,
                                    plane_assignment->fb_id,
                                    refresh_rate,
                                    page_flip_data);
        }
      else
        {
          g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,
                       "Page flip of %u failed, and no mode set available",
                       meta_kms_crtc_get_id (crtc));
          meta_kms_page_flip_data_unref (page_flip_data);
          return FALSE;
        }
    }
  else if (ret == -EINVAL)
    {
      if (!mode_set_fallback (impl_simple,
                              update,
                              page_flip,
                              plane_assignment,
                              page_flip_data,
                              error))
        {
          meta_kms_page_flip_data_unref (page_flip_data);
          return FALSE;
        }
    }
  else if (ret != 0)
    {
      g_set_error (error, G_IO_ERROR, g_io_error_from_errno (-ret),
                   "drmModePageFlip on CRTC %u failed: %s",
                   meta_kms_crtc_get_id (crtc),
                   g_strerror (-ret));
      meta_kms_page_flip_data_unref (page_flip_data);
      return FALSE;
    }

  meta_kms_page_flip_data_unref (page_flip_data);
  return TRUE;
}

static void
discard_page_flip (MetaKmsImpl     *impl,
                   MetaKmsUpdate   *update,
                   MetaKmsPageFlip *page_flip)
{
  MetaKmsCrtc *crtc;
  MetaKmsPageFlipData *page_flip_data;

  crtc = page_flip->crtc;
  page_flip_data = meta_kms_page_flip_data_new (impl,
                                                crtc,
                                                page_flip->feedback,
                                                page_flip->user_data);
  meta_kms_page_flip_data_discard_in_impl (page_flip_data, NULL);
  meta_kms_page_flip_data_unref (page_flip_data);
}

static gboolean
process_entries (MetaKmsImpl     *impl,
                 MetaKmsUpdate   *update,
                 GList           *entries,
                 gboolean      (* func) (MetaKmsImpl    *impl,
                                         MetaKmsUpdate  *update,
                                         gpointer        entry_data,
                                         GError        **error),
                 GError         **error)
{
  GList *l;

  for (l = entries; l; l = l->next)
    {
      if (!func (impl, update, l->data, error))
        return FALSE;
    }

  return TRUE;
}

static gboolean
process_cursor_plane_assignment (MetaKmsImpl             *impl,
                                 MetaKmsUpdate           *update,
                                 MetaKmsPlaneAssignment  *plane_assignment,
                                 GError                 **error)
{
  MetaKmsPlane *plane;
  MetaKmsDevice *device;
  MetaKmsImplDevice *impl_device;
  int fd;

  plane = plane_assignment->plane;
  device = meta_kms_plane_get_device (plane);
  impl_device = meta_kms_device_get_impl_device (device);
  fd = meta_kms_impl_device_get_fd (impl_device);

  if (!(plane_assignment->flags & META_KMS_ASSIGN_PLANE_FLAG_FB_UNCHANGED))
    {
      int width, height;
      int ret = -1;

      width = meta_fixed_16_to_int (plane_assignment->dst_rect.width);
      height = meta_fixed_16_to_int (plane_assignment->dst_rect.height);

      if (plane_assignment->cursor_hotspot.is_valid)
        {
          ret = drmModeSetCursor2 (fd, meta_kms_crtc_get_id (plane_assignment->crtc),
                                   plane_assignment->fb_id,
                                   width, height,
                                   plane_assignment->cursor_hotspot.x,
                                   plane_assignment->cursor_hotspot.y);
        }

      if (ret != 0)
        {
          ret = drmModeSetCursor (fd, meta_kms_crtc_get_id (plane_assignment->crtc),
                                  plane_assignment->fb_id,
                                  width, height);
        }

      if (ret != 0)
        {
          g_set_error (error, G_IO_ERROR, g_io_error_from_errno (-ret),
                       "drmModeSetCursor failed: %s", g_strerror (-ret));
          return FALSE;
        }
    }

  drmModeMoveCursor (fd,
                     meta_kms_crtc_get_id (plane_assignment->crtc),
                     meta_fixed_16_to_int (plane_assignment->dst_rect.x),
                     meta_fixed_16_to_int (plane_assignment->dst_rect.y));

  return TRUE;
}

static gboolean
process_plane_assignment (MetaKmsImpl             *impl,
                          MetaKmsUpdate           *update,
                          MetaKmsPlaneAssignment  *plane_assignment,
                          MetaKmsPlaneFeedback   **plane_feedback)
{
  MetaKmsPlane *plane;
  MetaKmsPlaneType plane_type;
  GError *error = NULL;

  plane = plane_assignment->plane;
  plane_type = meta_kms_plane_get_plane_type (plane);
  switch (plane_type)
    {
    case META_KMS_PLANE_TYPE_PRIMARY:
      /* Handled as part of the mode-set and page flip. */
      return TRUE;
    case META_KMS_PLANE_TYPE_CURSOR:
      if (!process_cursor_plane_assignment (impl, update,
                                            plane_assignment,
                                            &error))
        {
          *plane_feedback =
            meta_kms_plane_feedback_new_take_error (plane,
                                                    plane_assignment->crtc,
                                                    g_steal_pointer (&error));
          return FALSE;
        }
      else
        {
          return TRUE;
        }
    case META_KMS_PLANE_TYPE_OVERLAY:
      error = g_error_new_literal (G_IO_ERROR, G_IO_ERROR_FAILED,
                                   "Overlay planes cannot be assigned");
      *plane_feedback =
        meta_kms_plane_feedback_new_take_error (plane,
                                                plane_assignment->crtc,
                                                g_steal_pointer (&error));
      return TRUE;
    }

  g_assert_not_reached ();
}

static GList *
process_plane_assignments (MetaKmsImpl   *impl,
                           MetaKmsUpdate *update)
{
  GList *failed_planes = NULL;
  GList *l;

  for (l = meta_kms_update_get_plane_assignments (update); l; l = l->next)
    {
      MetaKmsPlaneAssignment *plane_assignment = l->data;
      MetaKmsPlaneFeedback *plane_feedback;

      if (!process_plane_assignment (impl, update, plane_assignment,
                                     &plane_feedback))
        failed_planes = g_list_prepend (failed_planes, plane_feedback);
    }

  return failed_planes;
}

static GList *
generate_all_failed_feedbacks (MetaKmsUpdate *update)
{
  GList *failed_planes = NULL;
  GList *l;

  for (l = meta_kms_update_get_plane_assignments (update); l; l = l->next)
    {
      MetaKmsPlaneAssignment *plane_assignment = l->data;
      MetaKmsPlane *plane;
      MetaKmsPlaneType plane_type;
      MetaKmsPlaneFeedback *plane_feedback;

      plane = plane_assignment->plane;
      plane_type = meta_kms_plane_get_plane_type (plane);
      switch (plane_type)
        {
        case META_KMS_PLANE_TYPE_PRIMARY:
          continue;
        case META_KMS_PLANE_TYPE_CURSOR:
        case META_KMS_PLANE_TYPE_OVERLAY:
          break;
        }

      plane_feedback =
        meta_kms_plane_feedback_new_take_error (plane_assignment->plane,
                                                plane_assignment->crtc,
                                                g_error_new (G_IO_ERROR,
                                                             G_IO_ERROR_FAILED,
                                                             "Discarded"));
      failed_planes = g_list_prepend (failed_planes, plane_feedback);
    }

  return failed_planes;
}

static MetaKmsFeedback *
meta_kms_impl_simple_process_update (MetaKmsImpl   *impl,
                                     MetaKmsUpdate *update)
{
  GError *error = NULL;
  GList *failed_planes;
  GList *l;

  meta_assert_in_kms_impl (meta_kms_impl_get_kms (impl));

  if (!process_entries (impl,
                        update,
                        meta_kms_update_get_connector_properties (update),
                        process_connector_property,
                        &error))
    goto err_planes_not_assigned;

  if (!process_entries (impl,
                        update,
                        meta_kms_update_get_mode_sets (update),
                        process_mode_set,
                        &error))
    goto err_planes_not_assigned;

  if (!process_entries (impl,
                        update,
                        meta_kms_update_get_crtc_gammas (update),
                        process_crtc_gamma,
                        &error))
    goto err_planes_not_assigned;

  failed_planes = process_plane_assignments (impl, update);
  if (failed_planes)
    {
      g_set_error (&error, G_IO_ERROR, G_IO_ERROR_FAILED,
                   "Failed to assign one or more planes");
      goto err_planes_assigned;
    }

  if (!process_entries (impl,
                        update,
                        meta_kms_update_get_page_flips (update),
                        process_page_flip,
                        &error))
    goto err_planes_assigned;

  return meta_kms_feedback_new_passed ();

err_planes_not_assigned:
  failed_planes = generate_all_failed_feedbacks (update);

err_planes_assigned:
  for (l = meta_kms_update_get_page_flips (update); l; l = l->next)
    {
      MetaKmsPageFlip *page_flip = l->data;

      discard_page_flip (impl, update, page_flip);
    }

  return meta_kms_feedback_new_failed (failed_planes, error);
}

static void
flush_postponed_page_flip_datas (MetaKmsImplSimple *impl_simple)
{
  invoke_page_flip_datas (impl_simple->postponed_page_flip_datas,
                          meta_kms_page_flip_data_flipped_in_impl);
  clear_page_flip_datas (&impl_simple->postponed_page_flip_datas);

  invoke_page_flip_datas (impl_simple->postponed_mode_set_fallback_datas,
                          meta_kms_page_flip_data_mode_set_fallback_in_impl);
  clear_page_flip_datas (&impl_simple->postponed_mode_set_fallback_datas);
}

static void
meta_kms_impl_simple_handle_page_flip_callback (MetaKmsImpl         *impl,
                                                MetaKmsPageFlipData *page_flip_data)
{
  MetaKmsImplSimple *impl_simple = META_KMS_IMPL_SIMPLE (impl);

  if (impl_simple->pending_page_flip_retries)
    {
      impl_simple->postponed_page_flip_datas =
        g_list_append (impl_simple->postponed_page_flip_datas,
                       meta_kms_page_flip_data_ref (page_flip_data));
    }
  else
    {
      meta_kms_page_flip_data_flipped_in_impl (page_flip_data);
    }

  meta_kms_page_flip_data_unref (page_flip_data);
}

static void
meta_kms_impl_simple_discard_pending_page_flips (MetaKmsImpl *impl)
{
  MetaKmsImplSimple *impl_simple = META_KMS_IMPL_SIMPLE (impl);
  GList *l;

  if (!impl_simple->pending_page_flip_retries)
    return;

  for (l = impl_simple->pending_page_flip_retries; l; l = l->next)
    {
      RetryPageFlipData *retry_page_flip_data = l->data;
      MetaKmsPageFlipData *page_flip_data;

      page_flip_data = g_steal_pointer (&retry_page_flip_data->page_flip_data);
      meta_kms_page_flip_data_discard_in_impl (page_flip_data, NULL);
      retry_page_flip_data_free (retry_page_flip_data);
    }
  g_clear_pointer (&impl_simple->pending_page_flip_retries, g_list_free);

  g_clear_pointer (&impl_simple->retry_page_flips_source,
                   g_source_destroy);
}

static void
meta_kms_impl_simple_dispatch_idle (MetaKmsImpl *impl)
{
  MetaKmsImplSimple *impl_simple = META_KMS_IMPL_SIMPLE (impl);

  if (impl_simple->mode_set_fallback_feedback_source)
    mode_set_fallback_feedback_idle (impl_simple);
}

static void
meta_kms_impl_simple_notify_device_created (MetaKmsImpl   *impl,
                                            MetaKmsDevice *device)
{
  GList *l;

  for (l = meta_kms_device_get_crtcs (device); l; l = l->next)
    {
      MetaKmsCrtc *crtc = l->data;
      MetaKmsPlane *plane;

      plane = meta_kms_device_get_cursor_plane_for (device, crtc);
      if (plane)
        continue;

      meta_kms_device_add_fake_plane_in_impl (device,
                                              META_KMS_PLANE_TYPE_CURSOR,
                                              crtc);
    }
}

static void
meta_kms_impl_simple_finalize (GObject *object)
{
  MetaKmsImplSimple *impl_simple = META_KMS_IMPL_SIMPLE (object);

  g_list_free_full (impl_simple->pending_page_flip_retries,
                    (GDestroyNotify) retry_page_flip_data_free);
  g_list_free_full (impl_simple->postponed_page_flip_datas,
                    (GDestroyNotify) meta_kms_page_flip_data_unref);
  g_list_free_full (impl_simple->postponed_mode_set_fallback_datas,
                    (GDestroyNotify) meta_kms_page_flip_data_unref);
  g_clear_pointer (&impl_simple->mode_set_fallback_feedback_source,
                   g_source_destroy);
  g_hash_table_destroy (impl_simple->cached_mode_sets);

  G_OBJECT_CLASS (meta_kms_impl_simple_parent_class)->finalize (object);
}

static void
meta_kms_impl_simple_init (MetaKmsImplSimple *impl_simple)
{
  impl_simple->cached_mode_sets =
    g_hash_table_new_full (NULL,
                           NULL,
                           NULL,
                           (GDestroyNotify) cached_mode_set_free);
}

static void
meta_kms_impl_simple_class_init (MetaKmsImplSimpleClass *klass)
{
  GObjectClass *object_class = G_OBJECT_CLASS (klass);
  MetaKmsImplClass *impl_class = META_KMS_IMPL_CLASS (klass);

  object_class->finalize = meta_kms_impl_simple_finalize;

  impl_class->process_update = meta_kms_impl_simple_process_update;
  impl_class->handle_page_flip_callback = meta_kms_impl_simple_handle_page_flip_callback;
  impl_class->discard_pending_page_flips = meta_kms_impl_simple_discard_pending_page_flips;
  impl_class->dispatch_idle = meta_kms_impl_simple_dispatch_idle;
  impl_class->notify_device_created = meta_kms_impl_simple_notify_device_created;
}
