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

diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c b/drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c
index ff14555372d09dec06016da145c60db6a569fe09..78d5fa230c165e9f7a0c784902e0189ee30afc78 100644 (file)
--- 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 4a60f5fca6b0bdc90d0fdf758c9196a26381120a..fec6ef1ae3b9839a5b5916d15b6f4a58b5e05692 100644 (file)
--- 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;