[Intel-gfx] [V14 4/5] drm/i915/dsi: Initiate frame request in cmd mode

[Kulkarni, Vandita]

> -----Original Message-----
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> Sent: Monday, September 28, 2020 3:48 PM
> To: Kulkarni, Vandita <vandita.kulkarni at intel.com>
> Cc: intel-gfx at lists.freedesktop.org; Nikula, Jani <jani.nikula at intel.com>
> Subject: Re: [V14 4/5] drm/i915/dsi: Initiate frame request in cmd mode
> 
> On Thu, Sep 24, 2020 at 06:12:08PM +0530, Vandita Kulkarni wrote:
> > In TE Gate mode or TE NO_GATE mode on every flip we need to set the
> > frame update request bit.
> > After this  bit is set transcoder hardware will automatically send the
> > frame data to the panel in case of TE NO_GATE mode, where it sends
> > after it receives the TE event in case of TE_GATE mode.
> > Once the frame data is sent to the panel, we see the frame counter
> > updating.
> >
> > v2: Use intel_de_read/write
> >
> > v3: remove the usage of private_flags
> >
> > v4: Use icl_dsi in func names if non static,
> >     fix code formatting issues. (Jani)
> >
> > v5: Send frame update request at the beginning of
> >     pipe_update_end, use crtc_state mode_flags (Ville)
> >
> > Signed-off-by: Vandita Kulkarni <vandita.kulkarni at intel.com>
> > ---
> >  drivers/gpu/drm/i915/display/icl_dsi.c      | 26 +++++++++++++++++++++
> >  drivers/gpu/drm/i915/display/intel_dsi.h    |  1 +
> >  drivers/gpu/drm/i915/display/intel_sprite.c |  7 ++++++
> >  3 files changed, 34 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/i915/display/icl_dsi.c
> > b/drivers/gpu/drm/i915/display/icl_dsi.c
> > index 2789020e20db..fe946a2e2082 100644
> > --- a/drivers/gpu/drm/i915/display/icl_dsi.c
> > +++ b/drivers/gpu/drm/i915/display/icl_dsi.c
> > @@ -205,6 +205,32 @@ static int dsi_send_pkt_payld(struct intel_dsi_host
> *host,
> >  	return 0;
> >  }
> >
> > +void icl_dsi_frame_update(struct intel_crtc_state *crtc_state) {
> > +	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
> > +	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
> > +	u32 tmp, mode_flags;
> > +	enum port port;
> > +
> > +	mode_flags = crtc_state->mode_flags;
> > +
> > +	/*
> > +	 * case 1 also covers dual link
> > +	 * In case of dual link, frame update should be set on
> > +	 * DSI_0
> > +	 */
> > +	if (mode_flags & I915_MODE_FLAG_DSI_USE_TE0)
> > +		port = PORT_A;
> > +	else if (mode_flags & I915_MODE_FLAG_DSI_USE_TE1)
> > +		port = PORT_B;
> > +	else
> > +		return;
> > +
> > +	tmp = intel_de_read(dev_priv, DSI_CMD_FRMCTL(port));
> > +	tmp |= DSI_FRAME_UPDATE_REQUEST;
> > +	intel_de_write(dev_priv, DSI_CMD_FRMCTL(port), tmp); }
> > +
> >  static void dsi_program_swing_and_deemphasis(struct intel_encoder
> > *encoder)  {
> >  	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
> diff
> > --git a/drivers/gpu/drm/i915/display/intel_dsi.h
> > b/drivers/gpu/drm/i915/display/intel_dsi.h
> > index 19f78a4022d3..625f2f1ae061 100644
> > --- a/drivers/gpu/drm/i915/display/intel_dsi.h
> > +++ b/drivers/gpu/drm/i915/display/intel_dsi.h
> > @@ -167,6 +167,7 @@ static inline u16 intel_dsi_encoder_ports(struct
> > intel_encoder *encoder)
> >
> >  /* icl_dsi.c */
> >  void icl_dsi_init(struct drm_i915_private *dev_priv);
> > +void icl_dsi_frame_update(struct intel_crtc_state *crtc_state);
> >
> >  /* intel_dsi.c */
> >  int intel_dsi_bitrate(const struct intel_dsi *intel_dsi); diff --git
> > a/drivers/gpu/drm/i915/display/intel_sprite.c
> > b/drivers/gpu/drm/i915/display/intel_sprite.c
> > index 63040cb0d4e1..eaee29e0f535 100644
> > --- a/drivers/gpu/drm/i915/display/intel_sprite.c
> > +++ b/drivers/gpu/drm/i915/display/intel_sprite.c
> > @@ -47,6 +47,7 @@
> >  #include "intel_frontbuffer.h"
> >  #include "intel_pm.h"
> >  #include "intel_psr.h"
> > +#include "intel_dsi.h"
> >  #include "intel_sprite.h"
> >
> >  int intel_usecs_to_scanlines(const struct drm_display_mode
> > *adjusted_mode, @@ -202,6 +203,12 @@ void
> intel_pipe_update_end(struct
> > intel_crtc_state *new_crtc_state)
> >
> >  	trace_intel_pipe_update_end(crtc, end_vbl_count, scanline_end);
> >
> > +	/*
> > +	 * Incase of mipi dsi command mode, we need to set frame update
> > +	 * request for every commit.
> > +	 */
> > +	icl_dsi_frame_update(new_crtc_state);
> 
> Calling something called icl_dsi_foo() unconditionally from platform agnostic
> code looks confusing. I'd add platform+intel_crtc_has_type() check here.

Ok, sure will add the check.

Thanks
Vandita
> 
> > +
> >  	/* We're still in the vblank-evade critical section, this can't race.
> >  	 * Would be slightly nice to just grab the vblank count and arm the
> >  	 * event outside of the critical section - the spinlock might spin
> > for a
> > --
> > 2.21.0.5.gaeb582a
> 
> --
> Ville Syrjälä
> Intel