Dynamically assign a right mixer to mdp5_crtc_state in the CRTC's
atomic_check path. Assigning the right mixer has some constraints,
i.e, only a few LMs can be paired together. Update mdp5_mixer_assign
to handle these constraints.
Firstly, we need to identify whether we need a right mixer or not.
At the moment, there are 2 scenarios where a right mixer might be
needed:
- If any of the planes connected to this CRTC is too wide (i.e, is
comprised of 2 hwpipes).
- If the CRTC's mode itself is too wide (i.e, a 4K mode on HDMI).
We implement both these checks in the mdp5_crtc_atomic_check(), and
pass 'need_right_mixer' to mdp5_setup_pipeline.
If a CRTC is already assigned a single mixer, and a new atomic commit
brings in a drm_plane that needs 2 hwpipes, we can successfully commit
this mode without requiring a full modeset, provided that we still use
the previously assigned mixer as the left mixer. If such an assignment
isn't possible, we'd need to do a full modeset. This scenario has been
ignored for now.
The mixer assignment code is a bit messy, considering we have at most
4 LM instances in hardware. This can probably be re-visited later with
simplified logic.
Signed-off-by: Archit Taneja <architt@xxxxxxxxxxxxxx>
---
drivers/gpu/drm/msm/mdp/mdp5/mdp5_crtc.c | 49 +++++++++++++---
drivers/gpu/drm/msm/mdp/mdp5/mdp5_mixer.c | 97 +++++++++++++++++++++++++++----
drivers/gpu/drm/msm/mdp/mdp5/mdp5_mixer.h | 5 +-
3 files changed, 129 insertions(+), 22 deletions(-)
diff --git a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_crtc.c b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_crtc.c
index d0559962f85b..42fef018c04e 100644
--- a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_crtc.c
+++ b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_crtc.c
@@ -455,7 +455,8 @@ static void mdp5_crtc_enable(struct drm_crtc *crtc)
}
int mdp5_crtc_setup_pipeline(struct drm_crtc *crtc,
- struct drm_crtc_state *new_crtc_state)
+ struct drm_crtc_state *new_crtc_state,
+ bool need_right_mixer)
{
struct mdp5_crtc_state *mdp5_cstate =
to_mdp5_crtc_state(new_crtc_state);
@@ -465,15 +466,32 @@ int mdp5_crtc_setup_pipeline(struct drm_crtc *crtc,
new_mixer = !pipeline->mixer;
+ if ((need_right_mixer && !pipeline->r_mixer) ||
+ (!need_right_mixer && pipeline->r_mixer))
+ new_mixer = true;
+
if (new_mixer) {
struct mdp5_hw_mixer *old_mixer = pipeline->mixer;
+ struct mdp5_hw_mixer *old_r_mixer = pipeline->r_mixer;
+ u32 caps;
+ int ret;
+
+ caps = MDP_LM_CAP_DISPLAY;
+ if (need_right_mixer)
+ caps |= MDP_LM_CAP_PAIR;
- pipeline->mixer = mdp5_mixer_assign(new_crtc_state->state, crtc,
- MDP_LM_CAP_DISPLAY);
- if (IS_ERR(pipeline->mixer))
- return PTR_ERR(pipeline->mixer);
+ ret = mdp5_mixer_assign(new_crtc_state->state, crtc, caps,
+ &pipeline->mixer, need_right_mixer ?
+ &pipeline->r_mixer : NULL);
+ if (ret)
+ return ret;
mdp5_mixer_release(new_crtc_state->state, old_mixer);
+ if (old_r_mixer) {
+ mdp5_mixer_release(new_crtc_state->state, old_r_mixer);
+ if (!need_right_mixer)
+ pipeline->r_mixer = NULL;
+ }
}
/*
@@ -550,7 +568,9 @@ static int mdp5_crtc_atomic_check(struct drm_crtc *crtc,
struct plane_state pstates[STAGE_MAX + 1];
const struct mdp5_cfg_hw *hw_cfg;
const struct drm_plane_state *pstate;
+ const struct drm_display_mode *mode = &state->adjusted_mode;
bool cursor_plane = false;
+ bool need_right_mixer = false;
int cnt = 0, i;
int ret;
enum mdp_mixer_stage_id start;
@@ -561,6 +581,12 @@ static int mdp5_crtc_atomic_check(struct drm_crtc *crtc,
pstates[cnt].plane = plane;
pstates[cnt].state = to_mdp5_plane_state(pstate);
+ /*
+ * if any plane on this crtc uses 2 hwpipes, then we need
+ * the crtc to have a right hwmixer.
+ */
+ if (pstates[cnt].state->r_hwpipe)
+ need_right_mixer = true;
cnt++;
if (plane->type == DRM_PLANE_TYPE_CURSOR)
@@ -571,7 +597,16 @@ static int mdp5_crtc_atomic_check(struct drm_crtc *crtc,
if (!cnt)
return 0;
- ret = mdp5_crtc_setup_pipeline(crtc, state);
+ hw_cfg = mdp5_cfg_get_hw_config(mdp5_kms->cfg);
+
+ /*
+ * we need a right hwmixer if the mode's width is greater than a single
+ * LM's max width
+ */
+ if (mode->hdisplay > hw_cfg->lm.max_width)
+ need_right_mixer = true;
+
+ ret = mdp5_crtc_setup_pipeline(crtc, state, need_right_mixer);
if (ret) {
dev_err(dev->dev, "couldn't assign mixers %d\n", ret);
return ret;
@@ -589,8 +624,6 @@ static int mdp5_crtc_atomic_check(struct drm_crtc *crtc,
/* verify that there are not too many planes attached to crtc
* and that we don't have conflicting mixer stages:
*/
- hw_cfg = mdp5_cfg_get_hw_config(mdp5_kms->cfg);
-
if ((cnt + start - 1) >= hw_cfg->lm.nb_stages) {
dev_err(dev->dev, "too many planes! cnt=%d, start stage=%d\n",
cnt, start);
diff --git a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_mixer.c b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_mixer.c
index 9bb1f824b2a9..8a00991f03c7 100644
--- a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_mixer.c
+++ b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_mixer.c
@@ -16,42 +16,115 @@
#include "mdp5_kms.h"
-struct mdp5_hw_mixer *mdp5_mixer_assign(struct drm_atomic_state *s,
- struct drm_crtc *crtc, uint32_t caps)
+/*
+ * As of now, there are only 2 combinations possible for source split:
+ *
+ * Left | Right
+ * -----|------
+ * LM0 | LM1
+ * LM2 | LM5
+ *
+ */
+static int lm_right_pair[] = { 1, -1, 5, -1, -1, -1 };
+
+static int get_right_pair_idx(struct mdp5_kms *mdp5_kms, int lm)
+{
+ int i;
+ int pair_lm;
+
+ pair_lm = lm_right_pair[lm];
+ if (pair_lm < 0)
+ return -EINVAL;
+
+ for (i = 0; i < mdp5_kms->num_hwmixers; i++) {
+ struct mdp5_hw_mixer *mixer = mdp5_kms->hwmixers[i];
+
+ if (mixer->lm == pair_lm)
+ return mixer->idx;
+ }
+
+ return -1;
+}
+
+int mdp5_mixer_assign(struct drm_atomic_state *s, struct drm_crtc *crtc,
+ uint32_t caps, struct mdp5_hw_mixer **mixer,
+ struct mdp5_hw_mixer **r_mixer)
{
struct msm_drm_private *priv = s->dev->dev_private;
struct mdp5_kms *mdp5_kms = to_mdp5_kms(to_mdp_kms(priv->kms));
struct mdp5_state *state = mdp5_get_state(s);
struct mdp5_hw_mixer_state *new_state;
- struct mdp5_hw_mixer *mixer = NULL;
int i;
if (IS_ERR(state))
- return ERR_CAST(state);
+ return PTR_ERR(state);
new_state = &state->hwmixer;
for (i = 0; i < mdp5_kms->num_hwmixers; i++) {
struct mdp5_hw_mixer *cur = mdp5_kms->hwmixers[i];
- /* skip if already in-use */
- if (new_state->hwmixer_to_crtc[cur->idx])
+ /*
+ * skip if already in-use by a different CRTC. If there is a
+ * mixer already assigned to this CRTC, it means this call is
+ * a request to get an additional right mixer. Assume that the
+ * existing mixer is the 'left' one, and try to see if we can
+ * get its corresponding 'right' pair.
+ */
+ if (new_state->hwmixer_to_crtc[cur->idx] &&
+ new_state->hwmixer_to_crtc[cur->idx] != crtc)
continue;
/* skip if doesn't support some required caps: */
if (caps & ~cur->caps)
continue;
- if (!mixer)
- mixer = cur;
+ if (r_mixer) {
+ int pair_idx;
+
+ pair_idx = get_right_pair_idx(mdp5_kms, cur->lm);
+ if (pair_idx < 0)
+ return -EINVAL;
+
+ if (new_state->hwmixer_to_crtc[pair_idx])
+ continue;
+
+ *r_mixer = mdp5_kms->hwmixers[pair_idx];
+ }
+
+ /*
+ * prefer a pair-able LM over an unpairable one. We can
+ * switch the CRTC from Normal mode to Source Split mode
+ * without requiring a full modeset if we had already
+ * assigned this CRTC a pair-able LM.
+ *
+ * TODO: There will be assignment sequences which would
+ * result in the CRTC requiring a full modeset, even
+ * if we have the LM resources to prevent it. For a platform
+ * with a few displays, we don't run out of pair-able LMs
+ * so easily. For now, ignore the possibility of requiring
+ * a full modeset.
+ */
+ if (!(*mixer) || cur->caps & MDP_LM_CAP_PAIR)
+ *mixer = cur;
}
- if (!mixer)
- return ERR_PTR(-ENOMEM);
+ if (!(*mixer))
+ return -ENOMEM;
- new_state->hwmixer_to_crtc[mixer->idx] = crtc;
+ if (r_mixer && !(*r_mixer))
+ return -ENOMEM;
- return mixer;
+ DBG("assigning Layer Mixer %d to crtc %s", (*mixer)->lm, crtc->name);
+
+ new_state->hwmixer_to_crtc[(*mixer)->idx] = crtc;
+ if (r_mixer) {
+ DBG("assigning Right Layer Mixer %d to crtc %s", (*r_mixer)->lm,
+ crtc->name);
+ new_state->hwmixer_to_crtc[(*r_mixer)->idx] = crtc;
+ }
+
+ return 0;
}
void mdp5_mixer_release(struct drm_atomic_state *s, struct mdp5_hw_mixer *mixer)
diff --git a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_mixer.h b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_mixer.h
index 18ed933ae574..9be94f567fbd 100644
--- a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_mixer.h
+++ b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_mixer.h
@@ -38,8 +38,9 @@ struct mdp5_hw_mixer_state {
struct mdp5_hw_mixer *mdp5_mixer_init(const struct mdp5_lm_instance *lm);
void mdp5_mixer_destroy(struct mdp5_hw_mixer *lm);
-struct mdp5_hw_mixer *mdp5_mixer_assign(struct drm_atomic_state *s,
- struct drm_crtc *crtc, uint32_t caps);
+int mdp5_mixer_assign(struct drm_atomic_state *s, struct drm_crtc *crtc,
+ uint32_t caps, struct mdp5_hw_mixer **mixer,
+ struct mdp5_hw_mixer **r_mixer);
void mdp5_mixer_release(struct drm_atomic_state *s,
struct mdp5_hw_mixer *mixer);
--
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