mutter/src/backends/native/meta-kms-crtc.c
Jonas Ådahl 27ed069766 kms/impl-device: Add deadline based KMS commit scheduling
This makes it possible to post KMS updates that will always defer until
just before the scanout deadline. This is useful to allow queuing cursor
updates where we don't want to post them to KMS immediately, but rather
wait until as late as possible to get lower latency.

We cannot delay primary plane compositions however, and this is due to
how the kernel may prioritize GPU work - not until a pipeline gets
attached to a atomic commit will it in some drivers get bumped to high
priority. This means we still need to post any update that depends on
OpenGL pipelines as soon as possible.

To avoid working on compositing, then getting stomped on the feet by the
deadline scheduler, the deadline timer is disarmed whenever there is a
frame currently being painted. This will still allow new cursor updates
to arrive during composition, but will delay the actual KMS commit until
the primary plane update has been posted.

Still, even for cursor-only we still need higher than default timing
capabilities, thus the deadline scheduler depends on the KMS thread
getting real-time scheduling priority. When the thread isn't realtime
scheduled, the KMS thread instead asks the main thread to "flush" the
commit as part of the regular frame update. A flushing update means one
that isn't set to always defer and has a latching CRTC.

The verbose KMS debug logging makes the processing take too long, making
us more likely to miss the deadline. Avoid this by increasing the
evasion length when debug logging is enabled. Not the best, but better
than changing the behavior completely.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2777>
2023-07-17 23:42:38 +02:00

583 lines
16 KiB
C

/*
* Copyright (C) 2019 Red Hat
*
* 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-crtc.h"
#include "backends/native/meta-kms-crtc-private.h"
#include "backends/native/meta-kms-device-private.h"
#include "backends/native/meta-kms-impl-device.h"
#include "backends/native/meta-kms-impl-device-atomic.h"
#include "backends/native/meta-kms-impl-device-simple.h"
#include "backends/native/meta-kms-mode.h"
#include "backends/native/meta-kms-update-private.h"
#include "backends/native/meta-kms-utils.h"
#define DEADLINE_EVASION_US 500
#define DEADLINE_EVASION_WITH_KMS_TOPIC_US 1000
typedef struct _MetaKmsCrtcPropTable
{
MetaKmsProp props[META_KMS_CRTC_N_PROPS];
} MetaKmsCrtcPropTable;
struct _MetaKmsCrtc
{
GObject parent;
MetaKmsDevice *device;
uint32_t id;
int idx;
MetaKmsCrtcState current_state;
MetaKmsCrtcPropTable prop_table;
};
G_DEFINE_TYPE (MetaKmsCrtc, meta_kms_crtc, G_TYPE_OBJECT)
MetaKmsDevice *
meta_kms_crtc_get_device (MetaKmsCrtc *crtc)
{
return crtc->device;
}
const MetaKmsCrtcState *
meta_kms_crtc_get_current_state (MetaKmsCrtc *crtc)
{
return &crtc->current_state;
}
uint32_t
meta_kms_crtc_get_id (MetaKmsCrtc *crtc)
{
return crtc->id;
}
int
meta_kms_crtc_get_idx (MetaKmsCrtc *crtc)
{
return crtc->idx;
}
uint32_t
meta_kms_crtc_get_prop_id (MetaKmsCrtc *crtc,
MetaKmsCrtcProp prop)
{
return crtc->prop_table.props[prop].prop_id;
}
const char *
meta_kms_crtc_get_prop_name (MetaKmsCrtc *crtc,
MetaKmsCrtcProp prop)
{
return crtc->prop_table.props[prop].name;
}
uint64_t
meta_kms_crtc_get_prop_drm_value (MetaKmsCrtc *crtc,
MetaKmsCrtcProp property,
uint64_t value)
{
MetaKmsProp *prop = &crtc->prop_table.props[property];
return meta_kms_prop_convert_value (prop, value);
}
gboolean
meta_kms_crtc_is_active (MetaKmsCrtc *crtc)
{
return crtc->current_state.is_active;
}
static void
read_crtc_gamma (MetaKmsCrtc *crtc,
MetaKmsCrtcState *crtc_state,
MetaKmsImplDevice *impl_device,
drmModeCrtc *drm_crtc)
{
MetaKmsProp *prop_lut;
MetaKmsProp *prop_size;
uint64_t blob_id;
uint64_t lut_size;
int fd;
drmModePropertyBlobPtr blob;
int drm_lut_size;
struct drm_color_lut *drm_lut;
int i;
prop_lut = &crtc->prop_table.props[META_KMS_CRTC_PROP_GAMMA_LUT];
prop_size = &crtc->prop_table.props[META_KMS_CRTC_PROP_GAMMA_LUT_SIZE];
if (!prop_lut->prop_id || !prop_size->prop_id)
return;
lut_size = prop_size->value;
if (lut_size <= 0)
return;
crtc_state->gamma.size = lut_size;
crtc_state->gamma.supported = TRUE;
blob_id = prop_lut->value;
if (blob_id == 0)
return;
fd = meta_kms_impl_device_get_fd (impl_device);
blob = drmModeGetPropertyBlob (fd, blob_id);
if (!blob)
return;
drm_lut_size = blob->length / sizeof (struct drm_color_lut);
if (drm_lut_size == 0)
{
drmModeFreePropertyBlob (blob);
return;
}
drm_lut = blob->data;
crtc_state->gamma.value = meta_gamma_lut_new_sized (drm_lut_size);
for (i = 0; i < drm_lut_size; i++)
{
crtc_state->gamma.value->red[i] = drm_lut[i].red;
crtc_state->gamma.value->green[i] = drm_lut[i].green;
crtc_state->gamma.value->blue[i] = drm_lut[i].blue;
}
drmModeFreePropertyBlob (blob);
}
static void
read_crtc_legacy_gamma (MetaKmsCrtc *crtc,
MetaKmsCrtcState *crtc_state,
MetaKmsImplDevice *impl_device,
drmModeCrtc *drm_crtc)
{
crtc_state->gamma.size = drm_crtc->gamma_size;
crtc_state->gamma.supported = drm_crtc->gamma_size != 0;
crtc_state->gamma.value = meta_gamma_lut_new_sized (drm_crtc->gamma_size);
drmModeCrtcGetGamma (meta_kms_impl_device_get_fd (impl_device),
crtc->id,
crtc_state->gamma.value->size,
crtc_state->gamma.value->red,
crtc_state->gamma.value->green,
crtc_state->gamma.value->blue);
}
static void
read_gamma_state (MetaKmsCrtc *crtc,
MetaKmsCrtcState *crtc_state,
MetaKmsImplDevice *impl_device,
drmModeCrtc *drm_crtc)
{
g_assert_null (crtc_state->gamma.value);
crtc_state->gamma.size = 0;
crtc_state->gamma.supported = FALSE;
if (META_IS_KMS_IMPL_DEVICE_ATOMIC (impl_device))
read_crtc_gamma (crtc, crtc_state, impl_device, drm_crtc);
else if (META_IS_KMS_IMPL_DEVICE_SIMPLE (impl_device))
read_crtc_legacy_gamma (crtc, crtc_state, impl_device, drm_crtc);
}
static gboolean
gamma_equal (MetaKmsCrtcState *state,
MetaKmsCrtcState *other_state)
{
return state->gamma.size == other_state->gamma.size &&
state->gamma.supported == other_state->gamma.supported &&
meta_gamma_lut_equal (state->gamma.value, other_state->gamma.value);
}
static MetaKmsResourceChanges
meta_kms_crtc_state_changes (MetaKmsCrtcState *state,
MetaKmsCrtcState *other_state)
{
if (state->is_active != other_state->is_active)
return META_KMS_RESOURCE_CHANGE_FULL;
if (!meta_rectangle_equal (&state->rect, &other_state->rect))
return META_KMS_RESOURCE_CHANGE_FULL;
if (state->is_drm_mode_valid != other_state->is_drm_mode_valid)
return META_KMS_RESOURCE_CHANGE_FULL;
if (!meta_drm_mode_equal (&state->drm_mode, &other_state->drm_mode))
return META_KMS_RESOURCE_CHANGE_FULL;
if (!gamma_equal (state, other_state))
return META_KMS_RESOURCE_CHANGE_GAMMA;
return META_KMS_RESOURCE_CHANGE_NONE;
}
static MetaKmsResourceChanges
meta_kms_crtc_read_state (MetaKmsCrtc *crtc,
MetaKmsImplDevice *impl_device,
drmModeCrtc *drm_crtc,
drmModeObjectProperties *drm_props)
{
MetaKmsCrtcState crtc_state = {0};
MetaKmsResourceChanges changes = META_KMS_RESOURCE_CHANGE_NONE;
MetaKmsProp *active_prop;
meta_kms_impl_device_update_prop_table (impl_device,
drm_props->props,
drm_props->prop_values,
drm_props->count_props,
crtc->prop_table.props,
META_KMS_CRTC_N_PROPS);
crtc_state.rect = (MetaRectangle) {
.x = drm_crtc->x,
.y = drm_crtc->y,
.width = drm_crtc->width,
.height = drm_crtc->height,
};
crtc_state.is_drm_mode_valid = drm_crtc->mode_valid;
crtc_state.drm_mode = drm_crtc->mode;
active_prop = &crtc->prop_table.props[META_KMS_CRTC_PROP_ACTIVE];
if (active_prop->prop_id)
crtc_state.is_active = !!active_prop->value;
else
crtc_state.is_active = drm_crtc->mode_valid;
read_gamma_state (crtc, &crtc_state, impl_device, drm_crtc);
if (!crtc_state.is_active)
{
if (crtc->current_state.is_active)
changes |= META_KMS_RESOURCE_CHANGE_FULL;
}
else
{
changes = meta_kms_crtc_state_changes (&crtc->current_state, &crtc_state);
}
g_clear_pointer (&crtc->current_state.gamma.value,
meta_gamma_lut_free);
crtc->current_state = crtc_state;
meta_topic (META_DEBUG_KMS,
"Read CRTC %u state: active: %d, mode: %s, changed: %s",
crtc->id, crtc->current_state.is_active,
crtc->current_state.is_drm_mode_valid
? crtc->current_state.drm_mode.name
: "(nil)",
changes == META_KMS_RESOURCE_CHANGE_NONE
? "no"
: "yes");
return changes;
}
MetaKmsResourceChanges
meta_kms_crtc_update_state_in_impl (MetaKmsCrtc *crtc)
{
MetaKmsImplDevice *impl_device;
MetaKmsResourceChanges changes;
int fd;
drmModeCrtc *drm_crtc;
drmModeObjectProperties *drm_props;
impl_device = meta_kms_device_get_impl_device (crtc->device);
fd = meta_kms_impl_device_get_fd (impl_device);
drm_crtc = drmModeGetCrtc (fd, crtc->id);
drm_props = drmModeObjectGetProperties (fd, crtc->id, DRM_MODE_OBJECT_CRTC);
if (!drm_crtc || !drm_props)
{
crtc->current_state.is_active = FALSE;
crtc->current_state.rect = (MetaRectangle) { };
crtc->current_state.is_drm_mode_valid = FALSE;
changes = META_KMS_RESOURCE_CHANGE_FULL;
goto out;
}
changes = meta_kms_crtc_read_state (crtc, impl_device, drm_crtc, drm_props);
out:
g_clear_pointer (&drm_props, drmModeFreeObjectProperties);
g_clear_pointer (&drm_crtc, drmModeFreeCrtc);
return changes;
}
void
meta_kms_crtc_disable_in_impl (MetaKmsCrtc *crtc)
{
crtc->current_state.is_active = FALSE;
crtc->current_state.rect = (MetaRectangle) { 0 };
crtc->current_state.is_drm_mode_valid = FALSE;
crtc->current_state.drm_mode = (drmModeModeInfo) { 0 };
}
void
meta_kms_crtc_predict_state_in_impl (MetaKmsCrtc *crtc,
MetaKmsUpdate *update)
{
GList *mode_sets;
GList *crtc_color_updates;
GList *l;
mode_sets = meta_kms_update_get_mode_sets (update);
for (l = mode_sets; l; l = l->next)
{
MetaKmsModeSet *mode_set = l->data;
if (mode_set->crtc != crtc)
continue;
if (mode_set->mode)
{
MetaKmsPlaneAssignment *plane_assignment;
const drmModeModeInfo *drm_mode;
plane_assignment =
meta_kms_update_get_primary_plane_assignment (update, crtc);
drm_mode = meta_kms_mode_get_drm_mode (mode_set->mode);
crtc->current_state.is_active = TRUE;
crtc->current_state.rect =
meta_fixed_16_rectangle_to_rectangle (plane_assignment->src_rect);
crtc->current_state.is_drm_mode_valid = TRUE;
crtc->current_state.drm_mode = *drm_mode;
}
else
{
crtc->current_state.is_active = FALSE;
crtc->current_state.rect = (MetaRectangle) { 0 };
crtc->current_state.is_drm_mode_valid = FALSE;
crtc->current_state.drm_mode = (drmModeModeInfo) { 0 };
}
break;
}
crtc_color_updates = meta_kms_update_get_crtc_color_updates (update);
for (l = crtc_color_updates; l; l = l->next)
{
MetaKmsCrtcColorUpdate *color_update = l->data;
MetaGammaLut *gamma = color_update->gamma.state;
if (color_update->crtc != crtc)
continue;
if (color_update->gamma.has_update)
{
if (gamma)
gamma = meta_gamma_lut_copy (gamma);
g_clear_pointer (&crtc->current_state.gamma.value, meta_gamma_lut_free);
crtc->current_state.gamma.value = gamma;
}
break;
}
}
static void
init_properties (MetaKmsCrtc *crtc,
MetaKmsImplDevice *impl_device,
drmModeCrtc *drm_crtc)
{
MetaKmsCrtcPropTable *prop_table = &crtc->prop_table;
*prop_table = (MetaKmsCrtcPropTable) {
.props = {
[META_KMS_CRTC_PROP_MODE_ID] =
{
.name = "MODE_ID",
.type = DRM_MODE_PROP_BLOB,
},
[META_KMS_CRTC_PROP_ACTIVE] =
{
.name = "ACTIVE",
.type = DRM_MODE_PROP_RANGE,
},
[META_KMS_CRTC_PROP_GAMMA_LUT] =
{
.name = "GAMMA_LUT",
.type = DRM_MODE_PROP_BLOB,
},
[META_KMS_CRTC_PROP_GAMMA_LUT_SIZE] =
{
.name = "GAMMA_LUT_SIZE",
.type = DRM_MODE_PROP_RANGE,
},
}
};
}
MetaKmsCrtc *
meta_kms_crtc_new (MetaKmsImplDevice *impl_device,
drmModeCrtc *drm_crtc,
int idx,
GError **error)
{
int fd;
drmModeObjectProperties *drm_props;
MetaKmsCrtc *crtc;
fd = meta_kms_impl_device_get_fd (impl_device);
drm_props = drmModeObjectGetProperties (fd, drm_crtc->crtc_id,
DRM_MODE_OBJECT_CRTC);
if (!drm_props)
{
g_set_error (error, G_IO_ERROR, g_io_error_from_errno (errno),
"drmModeObjectGetProperties: %s", g_strerror (errno));
return NULL;
}
crtc = g_object_new (META_TYPE_KMS_CRTC, NULL);
crtc->device = meta_kms_impl_device_get_device (impl_device);
crtc->id = drm_crtc->crtc_id;
crtc->idx = idx;
init_properties (crtc, impl_device, drm_crtc);
meta_kms_crtc_read_state (crtc, impl_device, drm_crtc, drm_props);
drmModeFreeObjectProperties (drm_props);
return crtc;
}
static void
meta_kms_crtc_finalize (GObject *object)
{
MetaKmsCrtc *crtc = META_KMS_CRTC (object);
g_clear_pointer (&crtc->current_state.gamma.value, meta_gamma_lut_free);
G_OBJECT_CLASS (meta_kms_crtc_parent_class)->finalize (object);
}
static void
meta_kms_crtc_init (MetaKmsCrtc *crtc)
{
crtc->current_state.gamma.size = 0;
crtc->current_state.gamma.value = NULL;
}
static void
meta_kms_crtc_class_init (MetaKmsCrtcClass *klass)
{
GObjectClass *object_class = G_OBJECT_CLASS (klass);
object_class->finalize = meta_kms_crtc_finalize;
}
static drmVBlankSeqType
get_crtc_type_bitmask (MetaKmsCrtc *crtc)
{
if (crtc->idx > 1)
{
return ((crtc->idx << DRM_VBLANK_HIGH_CRTC_SHIFT) &
DRM_VBLANK_HIGH_CRTC_MASK);
}
else if (crtc->idx > 0)
{
return DRM_VBLANK_SECONDARY;
}
else
{
return 0;
}
}
gboolean
meta_kms_crtc_determine_deadline (MetaKmsCrtc *crtc,
int64_t *out_next_deadline_us,
int64_t *out_next_presentation_us,
GError **error)
{
MetaKmsImplDevice *impl_device;
int fd;
drmVBlank vblank;
int ret;
int64_t next_presentation_us;
int64_t next_deadline_us;
drmModeModeInfo *drm_mode;
int64_t vblank_duration_us;
int64_t deadline_evasion_us;
if (!crtc->current_state.is_drm_mode_valid)
{
g_set_error (error, G_IO_ERROR, G_IO_ERROR_NOT_FOUND,
"Mode invalid");
return FALSE;
}
impl_device = meta_kms_device_get_impl_device (crtc->device);
fd = meta_kms_impl_device_get_fd (impl_device);
vblank = (drmVBlank) {
.request.type = DRM_VBLANK_RELATIVE | get_crtc_type_bitmask (crtc),
.request.sequence = 0,
.request.signal = 0,
};
ret = drmWaitVBlank (fd, &vblank);
if (ret != 0)
{
g_set_error (error, G_IO_ERROR, g_io_error_from_errno (-ret),
"drmWaitVBlank failed: %s", g_strerror (-ret));
return FALSE;
}
drm_mode = &crtc->current_state.drm_mode;
next_presentation_us =
s2us (vblank.reply.tval_sec) + vblank.reply.tval_usec + 0.5 +
G_USEC_PER_SEC / meta_calculate_drm_mode_refresh_rate (drm_mode);
/*
* 1
* time per pixel = -----------------
* Pixel clock (Hz)
*
* number of pixels = vdisplay * htotal
*
* time spent scanning out = time per pixel * number of pixels
*
*/
if (meta_is_topic_enabled (META_DEBUG_KMS))
deadline_evasion_us = DEADLINE_EVASION_WITH_KMS_TOPIC_US;
else
deadline_evasion_us = DEADLINE_EVASION_US;
vblank_duration_us = meta_calculate_drm_mode_vblank_duration_us (drm_mode);
next_deadline_us = next_presentation_us - (vblank_duration_us +
deadline_evasion_us);
*out_next_presentation_us = next_presentation_us;
*out_next_deadline_us = next_deadline_us;
return TRUE;
}