On 2018-11-13 12:52, Sean Paul wrote:
From: Sean Paul <seanpaul@xxxxxxxxxxxx>
Instead of assigning/clearing the crtc on vblank enable/disable, we can
just assign and clear the crtc on modeset. That allows us to just
toggle
the encoder's vblank interrupts on vblank_enable.
So why is this important? Previously the driver was using the legacy
pointers to assign/clear the crtc. Legacy pointers are cleared _after_
Which pointers are you referring here as legacy pointers? CRTC?
disabling the hardware, so the legacy pointer was valid during
vblank_disable, but that's not something we should rely on.
Instead of relying on the core ordering the legacy pointer assignments
just so, we'll assign the crtc in dpu_crtc enable/disable. This is the
only place that mapping can change, so we're covered there.
We're also taking advantage of drm_crtc_vblank_on/off. By using this,
we
ensure that vblank_enable/disable can never be called while the crtc is
off (which means the assigned crtc will always be valid). As such, we
What about the drm_vblank_enable/disable triggered by drm_vblank_get
when crtc
is disabled? What is the expected behavior there? the vblank_requested
variable removed by the next patch was introduced to cache the request.
don't need to use modeset locks or the crtc_lock in the
vblank_enable/disable routine to be sure state is consistent.
...I think.
Signed-off-by: Sean Paul <seanpaul@xxxxxxxxxxxx>
---
drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c | 77 +++++++++------------
drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c | 27 +++++---
drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h | 10 +++
3 files changed, 59 insertions(+), 55 deletions(-)
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
index 4b7f98a6ab60..59e823281fdf 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
@@ -757,43 +757,6 @@ void dpu_crtc_commit_kickoff(struct drm_crtc
*crtc)
DPU_ATRACE_END("crtc_commit");
}
-/**
- * _dpu_crtc_vblank_enable_no_lock - update power resource and vblank
request
- * @dpu_crtc: Pointer to dpu crtc structure
- * @enable: Whether to enable/disable vblanks
- */
-static void _dpu_crtc_vblank_enable_no_lock(
- struct dpu_crtc *dpu_crtc, bool enable)
-{
- struct drm_crtc *crtc = &dpu_crtc->base;
- struct drm_device *dev = crtc->dev;
- struct drm_encoder *enc;
-
- if (enable) {
- list_for_each_entry(enc, &dev->mode_config.encoder_list,
head) {
- if (enc->crtc != crtc)
- continue;
-
-
trace_dpu_crtc_vblank_enable(DRMID(&dpu_crtc->base),
- DRMID(enc), enable,
- dpu_crtc);
-
- dpu_encoder_assign_crtc(enc, crtc);
- }
- } else {
- list_for_each_entry(enc, &dev->mode_config.encoder_list,
head) {
- if (enc->crtc != crtc)
- continue;
-
-
trace_dpu_crtc_vblank_enable(DRMID(&dpu_crtc->base),
- DRMID(enc), enable,
- dpu_crtc);
-
- dpu_encoder_assign_crtc(enc, NULL);
- }
- }
-}
-
/**
* dpu_crtc_duplicate_state - state duplicate hook
* @crtc: Pointer to drm crtc structure
@@ -847,6 +810,10 @@ static void dpu_crtc_disable(struct drm_crtc
*crtc,
/* Disable/save vblank irq handling */
drm_crtc_vblank_off(crtc);
+ drm_for_each_encoder_mask(encoder, crtc->dev,
+ old_crtc_state->encoder_mask)
+ dpu_encoder_assign_crtc(encoder, NULL);
+
mutex_lock(&dpu_crtc->crtc_lock);
/* wait for frame_event_done completion */
@@ -856,9 +823,6 @@ static void dpu_crtc_disable(struct drm_crtc *crtc,
atomic_read(&dpu_crtc->frame_pending));
trace_dpu_crtc_disable(DRMID(crtc), false, dpu_crtc);
- if (dpu_crtc->enabled && dpu_crtc->vblank_requested) {
- _dpu_crtc_vblank_enable_no_lock(dpu_crtc, false);
- }
dpu_crtc->enabled = false;
if (atomic_read(&dpu_crtc->frame_pending)) {
@@ -922,13 +886,13 @@ static void dpu_crtc_enable(struct drm_crtc
*crtc,
mutex_lock(&dpu_crtc->crtc_lock);
trace_dpu_crtc_enable(DRMID(crtc), true, dpu_crtc);
- if (!dpu_crtc->enabled && dpu_crtc->vblank_requested) {
- _dpu_crtc_vblank_enable_no_lock(dpu_crtc, true);
- }
dpu_crtc->enabled = true;
mutex_unlock(&dpu_crtc->crtc_lock);
+ drm_for_each_encoder_mask(encoder, crtc->dev,
crtc->state->encoder_mask)
+ dpu_encoder_assign_crtc(encoder, crtc);
+
/* Enable/restore vblank irq handling */
drm_crtc_vblank_on(crtc);
}
@@ -1173,10 +1137,33 @@ static int dpu_crtc_atomic_check(struct
drm_crtc
*crtc,
int dpu_crtc_vblank(struct drm_crtc *crtc, bool en)
{
struct dpu_crtc *dpu_crtc = to_dpu_crtc(crtc);
+ struct drm_encoder *enc;
- mutex_lock(&dpu_crtc->crtc_lock);
trace_dpu_crtc_vblank(DRMID(&dpu_crtc->base), en, dpu_crtc);
- _dpu_crtc_vblank_enable_no_lock(dpu_crtc, en);
+
+ /*
+ * Normally we would iterate through encoder_mask in crtc state to
find
+ * attached encoders. In this case, we might be disabling vblank
_after_
+ * encoder_mask has been cleared.
+ *
+ * Instead, we "assign" a crtc to the encoder in enable and clear
it in
+ * disable (which is also after encoder_mask is cleared). So
instead of
+ * using encoder mask, we'll ask the encoder to toggle itself iff
it's
+ * currently assigned to our crtc.
+ *
+ * Note also that this function cannot be called while crtc is
disabled
+ * since we use drm_crtc_vblank_on/off. So we don't need to worry
+ * about the assigned crtcs being inconsistent with the current
state
+ * (which means no need to worry about modeset locks).
+ */
+ list_for_each_entry(enc, &crtc->dev->mode_config.encoder_list,
head) {
+ trace_dpu_crtc_vblank_enable(DRMID(crtc), DRMID(enc), en,
+ dpu_crtc);
+
+ dpu_encoder_toggle_vblank_for_crtc(enc, crtc, en);
+ }
+
+ mutex_lock(&dpu_crtc->crtc_lock);
dpu_crtc->vblank_requested = en;
mutex_unlock(&dpu_crtc->crtc_lock);
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
index fd6514f681ae..5914ae70572c 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
@@ -1267,22 +1267,29 @@ void dpu_encoder_assign_crtc(struct drm_encoder
*drm_enc, struct drm_crtc *crtc)
{
struct dpu_encoder_virt *dpu_enc = to_dpu_encoder_virt(drm_enc);
unsigned long lock_flags;
- bool enable;
- int i;
-
- enable = crtc ? true : false;
-
- if (!drm_enc) {
- DPU_ERROR("invalid encoder\n");
- return;
- }
- trace_dpu_enc_vblank_cb(DRMID(drm_enc), enable);
spin_lock_irqsave(&dpu_enc->enc_spinlock, lock_flags);
/* crtc should always be cleared before re-assigning */
WARN_ON(crtc && dpu_enc->crtc);
dpu_enc->crtc = crtc;
spin_unlock_irqrestore(&dpu_enc->enc_spinlock, lock_flags);
+}
+
+void dpu_encoder_toggle_vblank_for_crtc(struct drm_encoder *drm_enc,
+ struct drm_crtc *crtc, bool
enable)
+{
+ struct dpu_encoder_virt *dpu_enc = to_dpu_encoder_virt(drm_enc);
+ unsigned long lock_flags;
+ int i;
+
+ trace_dpu_enc_vblank_cb(DRMID(drm_enc), enable);
+
+ spin_lock_irqsave(&dpu_enc->enc_spinlock, lock_flags);
+ if (dpu_enc->crtc == crtc) {
+ spin_unlock_irqrestore(&dpu_enc->enc_spinlock,
lock_flags);
+ return;
+ }
Why are you returning when the crtc's are same?
Won't they be same all the time between modesets?
for both enable/disable crtc will be the same and you still need to call
the
for loop below to enable/disable the phys encoders.
+ spin_unlock_irqrestore(&dpu_enc->enc_spinlock, lock_flags);
for (i = 0; i < dpu_enc->num_phys_encs; i++) {
struct dpu_encoder_phys *phys = dpu_enc->phys_encs[i];
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h
b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h
index be1d80867834..6896ea2ab854 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h
@@ -62,6 +62,16 @@ void dpu_encoder_get_hw_resources(struct drm_encoder
*encoder,
void dpu_encoder_assign_crtc(struct drm_encoder *encoder,
struct drm_crtc *crtc);
+/**
+ * dpu_encoder_toggle_vblank_for_crtc - Toggles vblank interrupts on
or
off if
+ * the encoder is assigned to the given crtc
+ * @encoder: encoder pointer
+ * @crtc: crtc pointer
+ * @enable: true if vblank should be enabled
+ */
+void dpu_encoder_toggle_vblank_for_crtc(struct drm_encoder *encoder,
+ struct drm_crtc *crtc, bool
enable);
+
/**
* dpu_encoder_register_frame_event_callback - provide callback to
encoder that
* will be called after the request is complete, or other events.
--
Jeykumar S
