From 2bab52af6fe68c43b327a57e5ce5fc10eefdfadf Mon Sep 17 00:00:00 2001
From: Brian Masney <masneyb@onstation.org>
Date: Fri, 31 May 2019 05:46:15 -0400
Subject: [PATCH] drm/msm: add support for per-CRTC max_vblank_count on mdp5
The mdp5 drm/kms driver currently does not work on command-mode DSI
panels due to 'vblank wait timed out' errors. This causes a latency
of seconds, or tens of seconds in some cases, before content is shown
on the panel. This hardware does not have the something that we can use
as a frame counter available when running in command mode, so we need to
fall back to using timestamps by setting the max_vblank_count to zero.
This can be done on a per-CRTC basis, so the convert mdp5 to use
drm_crtc_set_max_vblank_count().
This change was tested on a LG Nexus 5 (hammerhead) phone.
Suggested-by: Jeffrey Hugo <jeffrey.l.hugo@gmail.com>
Reviewed-by: Jeffrey Hugo <jeffrey.l.hugo@gmail.com>
Signed-off-by: Brian Masney <masneyb@onstation.org>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190531094619.31704-3-masneyb@onstation.org
---
drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c | 16 +++++++++++++++-
drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c | 2 +-
2 files changed, 16 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c b/drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c
index ff14555372d09..78d5fa230c165 100644
--- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c
+++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c
@@ -439,6 +439,18 @@ static void mdp5_crtc_atomic_disable(struct drm_crtc *crtc,
mdp5_crtc->enabled = false;
}
+static void mdp5_crtc_vblank_on(struct drm_crtc *crtc)
+{
+ struct mdp5_crtc_state *mdp5_cstate = to_mdp5_crtc_state(crtc->state);
+ struct mdp5_interface *intf = mdp5_cstate->pipeline.intf;
+ u32 count;
+
+ count = intf->mode == MDP5_INTF_DSI_MODE_COMMAND ? 0 : 0xffffffff;
+ drm_crtc_set_max_vblank_count(crtc, count);
+
+ drm_crtc_vblank_on(crtc);
+}
+
static void mdp5_crtc_atomic_enable(struct drm_crtc *crtc,
struct drm_crtc_state *old_state)
{
@@ -475,7 +487,7 @@ static void mdp5_crtc_atomic_enable(struct drm_crtc *crtc,
}
/* Restore vblank irq handling after power is enabled */
- drm_crtc_vblank_on(crtc);
+ mdp5_crtc_vblank_on(crtc);
mdp5_crtc_mode_set_nofb(crtc);
@@ -1028,6 +1040,8 @@ static void mdp5_crtc_reset(struct drm_crtc *crtc)
mdp5_crtc_destroy_state(crtc, crtc->state);
__drm_atomic_helper_crtc_reset(crtc, &mdp5_cstate->base);
+
+ drm_crtc_vblank_reset(crtc);
}
static const struct drm_crtc_funcs mdp5_crtc_funcs = {
diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c b/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c
index 4a60f5fca6b0b..fec6ef1ae3b98 100644
--- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c
+++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c
@@ -740,7 +740,7 @@ struct msm_kms *mdp5_kms_init(struct drm_device *dev)
dev->driver->get_vblank_timestamp = drm_calc_vbltimestamp_from_scanoutpos;
dev->driver->get_scanout_position = mdp5_get_scanoutpos;
dev->driver->get_vblank_counter = mdp5_get_vblank_counter;
- dev->max_vblank_count = 0xffffffff;
+ dev->max_vblank_count = 0; /* max_vblank_count is set on each CRTC */
dev->vblank_disable_immediate = true;
return kms;
--
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