| Message ID | 20190531094619.31704-3-masneyb@onstation.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | ARM: qcom: working Nexus 5 display support | expand |
On Fri, May 31, 2019 at 3:46 AM Brian Masney <masneyb@onstation.org> wrote: > > 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. > > Signed-off-by: Brian Masney <masneyb@onstation.org> > Suggested-by: Jeffrey Hugo <jeffrey.l.hugo@gmail.com> Reviewed-by: Jeffrey Hugo <jeffrey.l.hugo@gmail.com> > --- > 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 c3751c95b452..6fde1097844f 100644 > --- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c > +++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c > @@ -450,6 +450,18 @@ 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) > { > @@ -486,7 +498,7 @@ 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); > > @@ -1039,6 +1051,8 @@ 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 97179bec8902..fcb0b0455abe 100644 > --- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c > +++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c > @@ -750,7 +750,7 @@ 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; > -- > 2.20.1 >
diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c b/drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c index c3751c95b452..6fde1097844f 100644 --- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c +++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_crtc.c @@ -450,6 +450,18 @@ 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) { @@ -486,7 +498,7 @@ 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); @@ -1039,6 +1051,8 @@ 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 97179bec8902..fcb0b0455abe 100644 --- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c +++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c @@ -750,7 +750,7 @@ 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;
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. Signed-off-by: Brian Masney <masneyb@onstation.org> Suggested-by: Jeffrey Hugo <jeffrey.l.hugo@gmail.com> --- 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(-)