|
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v3 2/4] drm: Initialize struct drm_crtc_state.no_vblank from device settings
At the end of a commit, atomic helpers can generate a VBLANK event
automatically. Originally implemented for writeback connectors, the
functionality can be used by any driver and/or hardware without proper
VBLANK interrupt.
First of all, the patch updates the documentation to make this behaviour
official: settings struct drm_crtc_state.no_vblank to true enables
automatic VBLANK generation.
Atomic modesetting helper set the initial value of no_vblank in
drm_atomic_helper_check_modeset(). If vblanking has been initialized
for a CRTC, no_blank is disabled. Otherwise it's enabled. Hence,
atomic helpers will automatically send out VBLANK events with any
driver that did not initialize vblanking.
As drivers previously send out VBLANK events by themselves, all
affected drivers have to be updated as well. Usually, deleting the
driver's vblanking code is sufficient. Xen implements its own logic
for generating events and therefore needs to override no_vblank
with a value of false.
v3:
* squash all related changes patches into this patch
Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
---
drivers/gpu/drm/arc/arcpgu_crtc.c | 16 --------------
drivers/gpu/drm/bochs/bochs_kms.c | 9 --------
drivers/gpu/drm/cirrus/cirrus.c | 8 -------
drivers/gpu/drm/drm_atomic_helper.c | 10 ++++++++-
drivers/gpu/drm/drm_mipi_dbi.c | 9 --------
drivers/gpu/drm/drm_vblank.c | 9 ++++++++
drivers/gpu/drm/qxl/qxl_display.c | 14 ------------
drivers/gpu/drm/tiny/gm12u320.c | 9 --------
drivers/gpu/drm/tiny/ili9225.c | 9 --------
drivers/gpu/drm/tiny/repaper.c | 9 --------
drivers/gpu/drm/tiny/st7586.c | 9 --------
drivers/gpu/drm/vboxvideo/vbox_mode.c | 12 -----------
drivers/gpu/drm/virtio/virtgpu_display.c | 8 -------
drivers/gpu/drm/xen/xen_drm_front_kms.c | 13 ++++++++++++
include/drm/drm_crtc.h | 27 ++++++++++++++++++------
include/drm/drm_simple_kms_helper.h | 7 ++++--
16 files changed, 56 insertions(+), 122 deletions(-)
diff --git a/drivers/gpu/drm/arc/arcpgu_crtc.c
b/drivers/gpu/drm/arc/arcpgu_crtc.c
index 8ae1e1f97a73..be7c29cec318 100644
--- a/drivers/gpu/drm/arc/arcpgu_crtc.c
+++ b/drivers/gpu/drm/arc/arcpgu_crtc.c
@@ -9,7 +9,6 @@
#include <drm/drm_device.h>
#include <drm/drm_fb_cma_helper.h>
#include <drm/drm_gem_cma_helper.h>
-#include <drm/drm_vblank.h>
#include <drm/drm_plane_helper.h>
#include <drm/drm_probe_helper.h>
#include <linux/clk.h>
@@ -138,24 +137,9 @@ static void arc_pgu_crtc_atomic_disable(struct drm_crtc
*crtc,
~ARCPGU_CTRL_ENABLE_MASK);
}
-static void arc_pgu_crtc_atomic_begin(struct drm_crtc *crtc,
- struct drm_crtc_state *state)
-{
- struct drm_pending_vblank_event *event = crtc->state->event;
-
- if (event) {
- crtc->state->event = NULL;
-
- spin_lock_irq(&crtc->dev->event_lock);
- drm_crtc_send_vblank_event(crtc, event);
- spin_unlock_irq(&crtc->dev->event_lock);
- }
-}
-
static const struct drm_crtc_helper_funcs arc_pgu_crtc_helper_funcs = {
.mode_valid = arc_pgu_crtc_mode_valid,
.mode_set_nofb = arc_pgu_crtc_mode_set_nofb,
- .atomic_begin = arc_pgu_crtc_atomic_begin,
.atomic_enable = arc_pgu_crtc_atomic_enable,
.atomic_disable = arc_pgu_crtc_atomic_disable,
};
diff --git a/drivers/gpu/drm/bochs/bochs_kms.c
b/drivers/gpu/drm/bochs/bochs_kms.c
index 3f0006c2470d..ff275faee88d 100644
--- a/drivers/gpu/drm/bochs/bochs_kms.c
+++ b/drivers/gpu/drm/bochs/bochs_kms.c
@@ -7,7 +7,6 @@
#include <drm/drm_atomic_helper.h>
#include <drm/drm_gem_framebuffer_helper.h>
#include <drm/drm_probe_helper.h>
-#include <drm/drm_vblank.h>
#include "bochs.h"
@@ -57,16 +56,8 @@ static void bochs_pipe_update(struct drm_simple_display_pipe
*pipe,
struct drm_plane_state *old_state)
{
struct bochs_device *bochs = pipe->crtc.dev->dev_private;
- struct drm_crtc *crtc = &pipe->crtc;
bochs_plane_update(bochs, pipe->plane.state);
-
- if (crtc->state->event) {
- spin_lock_irq(&crtc->dev->event_lock);
- drm_crtc_send_vblank_event(crtc, crtc->state->event);
- crtc->state->event = NULL;
- spin_unlock_irq(&crtc->dev->event_lock);
- }
}
static const struct drm_simple_display_pipe_funcs bochs_pipe_funcs = {
diff --git a/drivers/gpu/drm/cirrus/cirrus.c b/drivers/gpu/drm/cirrus/cirrus.c
index 248c9f765c45..a91fb0d7282c 100644
--- a/drivers/gpu/drm/cirrus/cirrus.c
+++ b/drivers/gpu/drm/cirrus/cirrus.c
@@ -38,7 +38,6 @@
#include <drm/drm_modeset_helper_vtables.h>
#include <drm/drm_probe_helper.h>
#include <drm/drm_simple_kms_helper.h>
-#include <drm/drm_vblank.h>
#define DRIVER_NAME "cirrus"
#define DRIVER_DESC "qemu cirrus vga"
@@ -434,13 +433,6 @@ static void cirrus_pipe_update(struct
drm_simple_display_pipe *pipe,
if (drm_atomic_helper_damage_merged(old_state, state, &rect))
cirrus_fb_blit_rect(pipe->plane.state->fb, &rect);
-
- if (crtc->state->event) {
- spin_lock_irq(&crtc->dev->event_lock);
- drm_crtc_send_vblank_event(crtc, crtc->state->event);
- crtc->state->event = NULL;
- spin_unlock_irq(&crtc->dev->event_lock);
- }
}
static const struct drm_simple_display_pipe_funcs cirrus_pipe_funcs = {
diff --git a/drivers/gpu/drm/drm_atomic_helper.c
b/drivers/gpu/drm/drm_atomic_helper.c
index 4511c2e07bb9..6e9c730a8919 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -583,6 +583,7 @@ mode_valid(struct drm_atomic_state *state)
* &drm_crtc_state.connectors_changed is set when a connector is added or
* removed from the CRTC. &drm_crtc_state.active_changed is set when
* &drm_crtc_state.active changes, which is used for DPMS.
+ * &drm_crtc_state.no_vblank is set from the result of drm_crtc_has_vblank().
* See also: drm_atomic_crtc_needs_modeset()
*
* IMPORTANT:
@@ -649,6 +650,11 @@ drm_atomic_helper_check_modeset(struct drm_device *dev,
return -EINVAL;
}
+
+ if (drm_crtc_has_vblank(crtc))
+ new_crtc_state->no_vblank = false;
+ else
+ new_crtc_state->no_vblank = true;
}
ret = handle_conflicting_encoders(state, false);
@@ -2215,7 +2221,9 @@ EXPORT_SYMBOL(drm_atomic_helper_wait_for_dependencies);
* when a job is queued, and any change to the pipeline that does not touch the
* connector is leading to timeouts when calling
* drm_atomic_helper_wait_for_vblanks() or
- * drm_atomic_helper_wait_for_flip_done().
+ * drm_atomic_helper_wait_for_flip_done(). In addition to writeback
+ * connectors, this function can also fake VBLANK events for CRTCs without
+ * VBLANK interrupt.
*
* This is part of the atomic helper support for nonblocking commits, see
* drm_atomic_helper_setup_commit() for an overview.
diff --git a/drivers/gpu/drm/drm_mipi_dbi.c b/drivers/gpu/drm/drm_mipi_dbi.c
index 16bff1be4b8a..13b753cb3f67 100644
--- a/drivers/gpu/drm/drm_mipi_dbi.c
+++ b/drivers/gpu/drm/drm_mipi_dbi.c
@@ -24,7 +24,6 @@
#include <drm/drm_modes.h>
#include <drm/drm_probe_helper.h>
#include <drm/drm_rect.h>
-#include <drm/drm_vblank.h>
#include <video/mipi_display.h>
#define MIPI_DBI_MAX_SPI_READ_SPEED 2000000 /* 2MHz */
@@ -299,18 +298,10 @@ void mipi_dbi_pipe_update(struct drm_simple_display_pipe
*pipe,
struct drm_plane_state *old_state)
{
struct drm_plane_state *state = pipe->plane.state;
- struct drm_crtc *crtc = &pipe->crtc;
struct drm_rect rect;
if (drm_atomic_helper_damage_merged(old_state, state, &rect))
mipi_dbi_fb_dirty(state->fb, &rect);
-
- if (crtc->state->event) {
- spin_lock_irq(&crtc->dev->event_lock);
- drm_crtc_send_vblank_event(crtc, crtc->state->event);
- spin_unlock_irq(&crtc->dev->event_lock);
- crtc->state->event = NULL;
- }
}
EXPORT_SYMBOL(mipi_dbi_pipe_update);
diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c
index c20102899411..d1d39ae47b0e 100644
--- a/drivers/gpu/drm/drm_vblank.c
+++ b/drivers/gpu/drm/drm_vblank.c
@@ -69,6 +69,12 @@
* &drm_driver.max_vblank_count. In that case the vblank core only disables the
* vblanks after a timer has expired, which can be configured through the
* ``vblankoffdelay`` module parameter.
+ *
+ * Drivers for hardware without support for vertical-blanking interrupts
+ * must not call drm_vblank_init(). For such drivers, atomic helpers will
+ * automatically generate vblank events as part of the display update. This
+ * functionality also can be controlled by the driver by enabling and disabling
+ * struct drm_crtc_state.no_vblank.
*/
/* Retry timestamp calculation up to 3 times to satisfy
@@ -510,6 +516,9 @@ EXPORT_SYMBOL(drm_vblank_init);
* initialized for a CRTC. For most hardware this means that vblanking
* can also be enabled on the CRTC.
*
+ * Atomic helpers use this function to initialize
+ * &drm_crtc_state.no_vblank. See also drm_atomic_helper_check_modeset().
+ *
* Returns:
* True if vblanking has been initialized for the given CRTC, false
* otherwise.
diff --git a/drivers/gpu/drm/qxl/qxl_display.c
b/drivers/gpu/drm/qxl/qxl_display.c
index 16d73b22f3f5..ab4f8dd00400 100644
--- a/drivers/gpu/drm/qxl/qxl_display.c
+++ b/drivers/gpu/drm/qxl/qxl_display.c
@@ -31,7 +31,6 @@
#include <drm/drm_gem_framebuffer_helper.h>
#include <drm/drm_plane_helper.h>
#include <drm/drm_probe_helper.h>
-#include <drm/drm_vblank.h>
#include "qxl_drv.h"
#include "qxl_object.h"
@@ -372,19 +371,6 @@ static void qxl_crtc_update_monitors_config(struct
drm_crtc *crtc,
static void qxl_crtc_atomic_flush(struct drm_crtc *crtc,
struct drm_crtc_state *old_crtc_state)
{
- struct drm_device *dev = crtc->dev;
- struct drm_pending_vblank_event *event;
- unsigned long flags;
-
- if (crtc->state && crtc->state->event) {
- event = crtc->state->event;
- crtc->state->event = NULL;
-
- spin_lock_irqsave(&dev->event_lock, flags);
- drm_crtc_send_vblank_event(crtc, event);
- spin_unlock_irqrestore(&dev->event_lock, flags);
- }
-
qxl_crtc_update_monitors_config(crtc, "flush");
}
diff --git a/drivers/gpu/drm/tiny/gm12u320.c b/drivers/gpu/drm/tiny/gm12u320.c
index 94fb1f593564..a48173441ae0 100644
--- a/drivers/gpu/drm/tiny/gm12u320.c
+++ b/drivers/gpu/drm/tiny/gm12u320.c
@@ -22,7 +22,6 @@
#include <drm/drm_modeset_helper_vtables.h>
#include <drm/drm_probe_helper.h>
#include <drm/drm_simple_kms_helper.h>
-#include <drm/drm_vblank.h>
static bool eco_mode;
module_param(eco_mode, bool, 0644);
@@ -610,18 +609,10 @@ static void gm12u320_pipe_update(struct
drm_simple_display_pipe *pipe,
struct drm_plane_state *old_state)
{
struct drm_plane_state *state = pipe->plane.state;
- struct drm_crtc *crtc = &pipe->crtc;
struct drm_rect rect;
if (drm_atomic_helper_damage_merged(old_state, state, &rect))
gm12u320_fb_mark_dirty(pipe->plane.state->fb, &rect);
-
- if (crtc->state->event) {
- spin_lock_irq(&crtc->dev->event_lock);
- drm_crtc_send_vblank_event(crtc, crtc->state->event);
- crtc->state->event = NULL;
- spin_unlock_irq(&crtc->dev->event_lock);
- }
}
static const struct drm_simple_display_pipe_funcs gm12u320_pipe_funcs = {
diff --git a/drivers/gpu/drm/tiny/ili9225.c b/drivers/gpu/drm/tiny/ili9225.c
index c66acc566c2b..802fb8dde1b6 100644
--- a/drivers/gpu/drm/tiny/ili9225.c
+++ b/drivers/gpu/drm/tiny/ili9225.c
@@ -26,7 +26,6 @@
#include <drm/drm_gem_framebuffer_helper.h>
#include <drm/drm_mipi_dbi.h>
#include <drm/drm_rect.h>
-#include <drm/drm_vblank.h>
#define ILI9225_DRIVER_READ_CODE 0x00
#define ILI9225_DRIVER_OUTPUT_CONTROL 0x01
@@ -165,18 +164,10 @@ static void ili9225_pipe_update(struct
drm_simple_display_pipe *pipe,
struct drm_plane_state *old_state)
{
struct drm_plane_state *state = pipe->plane.state;
- struct drm_crtc *crtc = &pipe->crtc;
struct drm_rect rect;
if (drm_atomic_helper_damage_merged(old_state, state, &rect))
ili9225_fb_dirty(state->fb, &rect);
-
- if (crtc->state->event) {
- spin_lock_irq(&crtc->dev->event_lock);
- drm_crtc_send_vblank_event(crtc, crtc->state->event);
- spin_unlock_irq(&crtc->dev->event_lock);
- crtc->state->event = NULL;
- }
}
static void ili9225_pipe_enable(struct drm_simple_display_pipe *pipe,
diff --git a/drivers/gpu/drm/tiny/repaper.c b/drivers/gpu/drm/tiny/repaper.c
index 76d179200775..183484595aea 100644
--- a/drivers/gpu/drm/tiny/repaper.c
+++ b/drivers/gpu/drm/tiny/repaper.c
@@ -33,7 +33,6 @@
#include <drm/drm_gem_framebuffer_helper.h>
#include <drm/drm_modes.h>
#include <drm/drm_rect.h>
-#include <drm/drm_vblank.h>
#include <drm/drm_probe_helper.h>
#include <drm/drm_simple_kms_helper.h>
@@ -856,18 +855,10 @@ static void repaper_pipe_update(struct
drm_simple_display_pipe *pipe,
struct drm_plane_state *old_state)
{
struct drm_plane_state *state = pipe->plane.state;
- struct drm_crtc *crtc = &pipe->crtc;
struct drm_rect rect;
if (drm_atomic_helper_damage_merged(old_state, state, &rect))
repaper_fb_dirty(state->fb);
-
- if (crtc->state->event) {
- spin_lock_irq(&crtc->dev->event_lock);
- drm_crtc_send_vblank_event(crtc, crtc->state->event);
- spin_unlock_irq(&crtc->dev->event_lock);
- crtc->state->event = NULL;
- }
}
static const struct drm_simple_display_pipe_funcs repaper_pipe_funcs = {
diff --git a/drivers/gpu/drm/tiny/st7586.c b/drivers/gpu/drm/tiny/st7586.c
index 060cc756194f..9ef559dd3191 100644
--- a/drivers/gpu/drm/tiny/st7586.c
+++ b/drivers/gpu/drm/tiny/st7586.c
@@ -23,7 +23,6 @@
#include <drm/drm_gem_framebuffer_helper.h>
#include <drm/drm_mipi_dbi.h>
#include <drm/drm_rect.h>
-#include <drm/drm_vblank.h>
/* controller-specific commands */
#define ST7586_DISP_MODE_GRAY 0x38
@@ -159,18 +158,10 @@ static void st7586_pipe_update(struct
drm_simple_display_pipe *pipe,
struct drm_plane_state *old_state)
{
struct drm_plane_state *state = pipe->plane.state;
- struct drm_crtc *crtc = &pipe->crtc;
struct drm_rect rect;
if (drm_atomic_helper_damage_merged(old_state, state, &rect))
st7586_fb_dirty(state->fb, &rect);
-
- if (crtc->state->event) {
- spin_lock_irq(&crtc->dev->event_lock);
- drm_crtc_send_vblank_event(crtc, crtc->state->event);
- spin_unlock_irq(&crtc->dev->event_lock);
- crtc->state->event = NULL;
- }
}
static void st7586_pipe_enable(struct drm_simple_display_pipe *pipe,
diff --git a/drivers/gpu/drm/vboxvideo/vbox_mode.c
b/drivers/gpu/drm/vboxvideo/vbox_mode.c
index 19612132c8a3..8b7f005c4d20 100644
--- a/drivers/gpu/drm/vboxvideo/vbox_mode.c
+++ b/drivers/gpu/drm/vboxvideo/vbox_mode.c
@@ -18,7 +18,6 @@
#include <drm/drm_gem_framebuffer_helper.h>
#include <drm/drm_plane_helper.h>
#include <drm/drm_probe_helper.h>
-#include <drm/drm_vblank.h>
#include "hgsmi_channels.h"
#include "vbox_drv.h"
@@ -226,17 +225,6 @@ static void vbox_crtc_atomic_disable(struct drm_crtc *crtc,
static void vbox_crtc_atomic_flush(struct drm_crtc *crtc,
struct drm_crtc_state *old_crtc_state)
{
- struct drm_pending_vblank_event *event;
- unsigned long flags;
-
- if (crtc->state && crtc->state->event) {
- event = crtc->state->event;
- crtc->state->event = NULL;
-
- spin_lock_irqsave(&crtc->dev->event_lock, flags);
- drm_crtc_send_vblank_event(crtc, event);
- spin_unlock_irqrestore(&crtc->dev->event_lock, flags);
- }
}
static const struct drm_crtc_helper_funcs vbox_crtc_helper_funcs = {
diff --git a/drivers/gpu/drm/virtio/virtgpu_display.c
b/drivers/gpu/drm/virtio/virtgpu_display.c
index 0966208ec30d..ecf4ba7cc32b 100644
--- a/drivers/gpu/drm/virtio/virtgpu_display.c
+++ b/drivers/gpu/drm/virtio/virtgpu_display.c
@@ -30,7 +30,6 @@
#include <drm/drm_fourcc.h>
#include <drm/drm_gem_framebuffer_helper.h>
#include <drm/drm_probe_helper.h>
-#include <drm/drm_vblank.h>
#include "virtgpu_drv.h"
@@ -121,13 +120,6 @@ static int virtio_gpu_crtc_atomic_check(struct drm_crtc
*crtc,
static void virtio_gpu_crtc_atomic_flush(struct drm_crtc *crtc,
struct drm_crtc_state *old_state)
{
- unsigned long flags;
-
- spin_lock_irqsave(&crtc->dev->event_lock, flags);
- if (crtc->state->event)
- drm_crtc_send_vblank_event(crtc, crtc->state->event);
- crtc->state->event = NULL;
- spin_unlock_irqrestore(&crtc->dev->event_lock, flags);
}
static const struct drm_crtc_helper_funcs virtio_gpu_crtc_helper_funcs = {
diff --git a/drivers/gpu/drm/xen/xen_drm_front_kms.c
b/drivers/gpu/drm/xen/xen_drm_front_kms.c
index 4f34c5208180..efde4561836f 100644
--- a/drivers/gpu/drm/xen/xen_drm_front_kms.c
+++ b/drivers/gpu/drm/xen/xen_drm_front_kms.c
@@ -220,6 +220,18 @@ static bool display_send_page_flip(struct
drm_simple_display_pipe *pipe,
return false;
}
+static int display_check(struct drm_simple_display_pipe *pipe,
+ struct drm_plane_state *plane_state,
+ struct drm_crtc_state *crtc_state)
+{
+ /* Make sure that DRM helpers don't send VBLANK events
+ * automatically. Xen has it's own logic to do so.
+ */
+ crtc_state->no_vblank = false;
+
+ return 0;
+}
+
static void display_update(struct drm_simple_display_pipe *pipe,
struct drm_plane_state *old_plane_state)
{
@@ -284,6 +296,7 @@ static const struct drm_simple_display_pipe_funcs
display_funcs = {
.enable = display_enable,
.disable = display_disable,
.prepare_fb = drm_gem_fb_simple_display_pipe_prepare_fb,
+ .check = display_check,
.update = display_update,
};
diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index 5e9b15a0e8c5..5363e31c9abe 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -174,12 +174,22 @@ struct drm_crtc_state {
* @no_vblank:
*
* Reflects the ability of a CRTC to send VBLANK events. This state
- * usually depends on the pipeline configuration, and the main usuage
- * is CRTCs feeding a writeback connector operating in oneshot mode.
- * In this case the VBLANK event is only generated when a job is queued
- * to the writeback connector, and we want the core to fake VBLANK
- * events when this part of the pipeline hasn't changed but others had
- * or when the CRTC and connectors are being disabled.
+ * usually depends on the pipeline configuration. If set to true, DRM
+ * atomic helpers will sendout a fake VBLANK event during display
+ * updates.
+ *
+ * One usage is for drivers and/or hardware without support for VBLANK
+ * interrupts. Such drivers typically do not initialize vblanking
+ * (i.e., call drm_vblank_init() wit the number of CRTCs). For CRTCs
+ * without initialized vblanking, the field is initialized to true and
+ * a VBLANK event will be send out on each update of the display
+ * pipeline.
+ *
+ * Another usage is CRTCs feeding a writeback connector operating in
+ * oneshot mode. In this case the VBLANK event is only generated when
+ * a job is queued to the writeback connector, and we want the core
+ * to fake VBLANK events when this part of the pipeline hasn't changed
+ * but others had or when the CRTC and connectors are being disabled.
*
* __drm_atomic_helper_crtc_duplicate_state() will not reset the value
* from the current state, the CRTC driver is then responsible for
@@ -335,7 +345,10 @@ struct drm_crtc_state {
* - Events for disabled CRTCs are not allowed, and drivers can ignore
* that case.
*
- * This can be handled by the drm_crtc_send_vblank_event() function,
+ * For very simple hardware without VBLANK interrupt, enabling
+ * &struct drm_crtc_state.no_vblank makes DRM's atomic commit helpers
+ * send the event at an appropriate time. For more complex hardware this
+ * can be handled by the drm_crtc_send_vblank_event() function,
* which the driver should call on the provided event upon completion of
* the atomic commit. Note that if the driver supports vblank signalling
* and timestamping the vblank counters and timestamps must agree with
diff --git a/include/drm/drm_simple_kms_helper.h
b/include/drm/drm_simple_kms_helper.h
index 15afee9cf049..e253ba7bea9d 100644
--- a/include/drm/drm_simple_kms_helper.h
+++ b/include/drm/drm_simple_kms_helper.h
@@ -100,8 +100,11 @@ struct drm_simple_display_pipe_funcs {
* This is the function drivers should submit the
* &drm_pending_vblank_event from. Using either
* drm_crtc_arm_vblank_event(), when the driver supports vblank
- * interrupt handling, or drm_crtc_send_vblank_event() directly in case
- * the hardware lacks vblank support entirely.
+ * interrupt handling, or drm_crtc_send_vblank_event() for more
+ * complex case. In case the hardware lacks vblank support entirely,
+ * drivers can set &struct drm_crtc_state.no_vblank in
+ * &struct drm_simple_display_pipe_funcs.check and let DRM's
+ * atomic helper fake a vblank event.
*/
void (*update)(struct drm_simple_display_pipe *pipe,
struct drm_plane_state *old_plane_state);
--
2.24.1
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel
|
 |
Lists.xenproject.org is hosted with RackSpace, monitoring our |