[Intel-gfx] [RFC 4/7] drm/i915/dsi: Helper to find dsi encoder in cmd mode

[Kulkarni, Vandita]

> -----Original Message-----
> From: Nikula, Jani <jani.nikula at intel.com>
> Sent: Wednesday, October 16, 2019 12:51 AM
> To: Kulkarni, Vandita <vandita.kulkarni at intel.com>; intel-
> gfx at lists.freedesktop.org
> Cc: ville.syrjala at linux.intel.com; Shankar, Uma <uma.shankar at intel.com>;
> Chauhan, Madhav <madhav.chauhan at intel.com>; Kulkarni, Vandita
> <vandita.kulkarni at intel.com>
> Subject: Re: [RFC 4/7] drm/i915/dsi: Helper to find dsi encoder in cmd mode
> 
> On Mon, 14 Oct 2019, Vandita Kulkarni <vandita.kulkarni at intel.com> wrote:
> > From: Madhav Chauhan <madhav.chauhan at intel.com>
> >
> > This patch adds a helper function to find encoder if DSI is operating
> > in command mode. This function will be used while enabling/disabling
> > TE interrupts for DSI.
> >
> > Signed-off-by: Madhav Chauhan <madhav.chauhan at intel.com>
> > Signed-off-by: Vandita Kulkarni <vandita.kulkarni at intel.com>
> > ---
> >  drivers/gpu/drm/i915/display/icl_dsi.c   | 17 +++++++++++++++++
> >  drivers/gpu/drm/i915/display/intel_dsi.h |  3 +++
> >  2 files changed, 20 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/i915/display/icl_dsi.c
> > b/drivers/gpu/drm/i915/display/icl_dsi.c
> > index 5dd9eebab6b1..877746416e52 100644
> > --- a/drivers/gpu/drm/i915/display/icl_dsi.c
> > +++ b/drivers/gpu/drm/i915/display/icl_dsi.c
> > @@ -73,6 +73,23 @@ static enum transcoder
> dsi_port_to_transcoder(enum port port)
> >  		return TRANSCODER_DSI_1;
> >  }
> >
> > +struct intel_encoder *gen11_dsi_find_cmd_mode_encoder(struct
> > +intel_crtc *crtc) {
> > +	struct drm_device *dev = crtc->base.dev;
> > +	struct intel_encoder *encoder;
> > +	struct intel_dsi *intel_dsi;
> > +
> > +	for_each_encoder_on_crtc(dev, &crtc->base, encoder) {
> > +		if (encoder->type != INTEL_OUTPUT_DSI)
> > +			continue;
> > +		intel_dsi = enc_to_intel_dsi(&encoder->base);
> > +		if (intel_dsi->operation_mode ==
> INTEL_DSI_COMMAND_MODE)
> > +			return encoder;
> > +	}
> > +
> > +	return NULL;
> > +}
> 
> This may be a bit harsh, but everything that feels wrong about the following
> patches pretty much boils down to this function. It may get the job done,
> and I don't have a better suggestion on how to accomplish this right now.
> But it seems like we shouldn't have to do anything like this, and makes you
> feel like there's something wrong with the design.
> 
> It would be great to be able to handle this using crtc state, but alas the
> vblank enable hook only gets passed a struct drm_crtc *. (Patch 7 could
> easily switch to using crtc state, but need to also solve patch
> 5.)
.
> 
> I'll get back to you on this later, but in the mean time - Ville, do you have
> any ideas?

Other option of adding in crtc_state, did you mean something like this
https://patchwork.freedesktop.org/patch/336178/ 
@Jani and @Ville  Please let me know your comments.

Thanks,
Vandita
> 
> 
> BR,
> Jani.
> 
> 
> > +
> >  static void wait_for_cmds_dispatched_to_panel(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 b15be5814599..071dad7ee04a 100644
> > --- a/drivers/gpu/drm/i915/display/intel_dsi.h
> > +++ b/drivers/gpu/drm/i915/display/intel_dsi.h
> > @@ -201,6 +201,9 @@ u32 bxt_dsi_get_pclk(struct intel_encoder
> *encoder,
> >  		     struct intel_crtc_state *config);  void
> > bxt_dsi_reset_clocks(struct intel_encoder *encoder, enum port port);
> >
> > +/* icl_dsi.c */
> > +struct intel_encoder *gen11_dsi_find_cmd_mode_encoder(struct
> > +intel_crtc *crtc);
> > +
> >  /* intel_dsi_vbt.c */
> >  bool intel_dsi_vbt_init(struct intel_dsi *intel_dsi, u16 panel_id);
> > void intel_dsi_vbt_exec_sequence(struct intel_dsi *intel_dsi,
> 
> --
> Jani Nikula, Intel Open Source Graphics Center