linux/drivers/gpu/drm/msm/mdp/mdp5/mdp5_mixer.h
Archit Taneja 8480adacfd drm/msm/mdp5: Assign 'right' mixer to CRTC state
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@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>
2017-04-08 06:59:36 -04:00

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1.5 KiB
C

/*
* Copyright (C) 2017 The Linux Foundation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*
* 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, see <http://www.gnu.org/licenses/>.
*/
#ifndef __MDP5_LM_H__
#define __MDP5_LM_H__
/* represents a hw Layer Mixer, one (or more) is dynamically assigned to a crtc */
struct mdp5_hw_mixer {
int idx;
const char *name;
int lm; /* the LM instance # */
uint32_t caps;
int pp;
int dspp;
uint32_t flush_mask; /* used to commit LM registers */
};
/* global atomic state of assignment between CRTCs and Layer Mixers: */
struct mdp5_hw_mixer_state {
struct drm_crtc *hwmixer_to_crtc[8];
};
struct mdp5_hw_mixer *mdp5_mixer_init(const struct mdp5_lm_instance *lm);
void mdp5_mixer_destroy(struct mdp5_hw_mixer *lm);
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);
#endif /* __MDP5_LM_H__ */