Re: [PATCH 06/11] drm/i915/cdclk: Extract vlv_dsi_min_cdclk()

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Wed, Oct 30, 2024 at 01:34:38PM +0200, Jani Nikula wrote:
> On Tue, 29 Oct 2024, Ville Syrjala <ville.syrjala@linux.intel.com> wrote:
> > From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> >
> > Pull the DSI min cdclk calculation into a helper and hide
> > it inside vlv_dsi.c in order to keep most DSI related
> > details in one place.
> >
> > Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > ---
> >  drivers/gpu/drm/i915/display/intel_cdclk.c | 23 ++------------------
> >  drivers/gpu/drm/i915/display/vlv_dsi.c     | 25 ++++++++++++++++++++++
> >  drivers/gpu/drm/i915/display/vlv_dsi.h     |  8 +++++++
> >  3 files changed, 35 insertions(+), 21 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/display/intel_cdclk.c b/drivers/gpu/drm/i915/display/intel_cdclk.c
> > index 89d12c521411..e10378744607 100644
> > --- a/drivers/gpu/drm/i915/display/intel_cdclk.c
> > +++ b/drivers/gpu/drm/i915/display/intel_cdclk.c
> > @@ -46,6 +46,7 @@
> >  #include "intel_vdsc.h"
> >  #include "skl_watermark.h"
> >  #include "skl_watermark_regs.h"
> > +#include "vlv_dsi.h"
> >  #include "vlv_sideband.h"
> >  
> >  /**
> > @@ -2849,8 +2850,6 @@ static int intel_vdsc_min_cdclk(const struct intel_crtc_state *crtc_state)
> >  
> >  int intel_crtc_compute_min_cdclk(const struct intel_crtc_state *crtc_state)
> >  {
> > -	struct intel_display *display = to_intel_display(crtc_state);
> > -	struct drm_i915_private *dev_priv = to_i915(display->drm);
> >  	int min_cdclk;
> >  
> >  	if (!crtc_state->hw.enable)
> > @@ -2859,25 +2858,7 @@ int intel_crtc_compute_min_cdclk(const struct intel_crtc_state *crtc_state)
> >  	min_cdclk = intel_pixel_rate_to_cdclk(crtc_state);
> >  	min_cdclk = max(hsw_ips_min_cdclk(crtc_state), min_cdclk);
> >  	min_cdclk = max(intel_audio_min_cdclk(crtc_state), min_cdclk);
> > -
> > -	/*
> > -	 * On Valleyview some DSI panels lose (v|h)sync when the clock is lower
> > -	 * than 320000KHz.
> > -	 */
> > -	if (intel_crtc_has_type(crtc_state, INTEL_OUTPUT_DSI) &&
> > -	    IS_VALLEYVIEW(dev_priv))
> > -		min_cdclk = max(320000, min_cdclk);
> > -
> > -	/*
> > -	 * On Geminilake once the CDCLK gets as low as 79200
> > -	 * picture gets unstable, despite that values are
> > -	 * correct for DSI PLL and DE PLL.
> > -	 */
> > -	if (intel_crtc_has_type(crtc_state, INTEL_OUTPUT_DSI) &&
> > -	    IS_GEMINILAKE(dev_priv))
> > -		min_cdclk = max(158400, min_cdclk);
> > -
> > -	/* Account for additional needs from the planes */
> > +	min_cdclk = max(vlv_dsi_min_cdclk(crtc_state), min_cdclk);
> >  	min_cdclk = max(intel_planes_min_cdclk(crtc_state), min_cdclk);
> >  
> >  	if (crtc_state->dsc.compression_enable)
> > diff --git a/drivers/gpu/drm/i915/display/vlv_dsi.c b/drivers/gpu/drm/i915/display/vlv_dsi.c
> > index 9383eedee2d4..49a895589150 100644
> > --- a/drivers/gpu/drm/i915/display/vlv_dsi.c
> > +++ b/drivers/gpu/drm/i915/display/vlv_dsi.c
> > @@ -1760,6 +1760,31 @@ static void vlv_dphy_param_init(struct intel_dsi *intel_dsi)
> >  	intel_dsi_log_params(intel_dsi);
> >  }
> >  
> > +int vlv_dsi_min_cdclk(const struct intel_crtc_state *crtc_state)
> > +{
> > +	struct drm_i915_private *dev_priv = to_i915(crtc_state->uapi.crtc->dev);
> > +	int min_cdclk = 0;
> > +
> > +	/*
> > +	 * On Valleyview some DSI panels lose (v|h)sync when the clock is lower
> > +	 * than 320000KHz.
> > +	 */
> > +	if (intel_crtc_has_type(crtc_state, INTEL_OUTPUT_DSI) &&
> > +	    IS_VALLEYVIEW(dev_priv))
> > +		min_cdclk = max(320000, min_cdclk);
> > +
> > +	/*
> > +	 * On Geminilake once the CDCLK gets as low as 79200
> > +	 * picture gets unstable, despite that values are
> > +	 * correct for DSI PLL and DE PLL.
> > +	 */
> > +	if (intel_crtc_has_type(crtc_state, INTEL_OUTPUT_DSI) &&
> > +	    IS_GEMINILAKE(dev_priv))
> > +		min_cdclk = max(158400, min_cdclk);
> > +
> > +	return min_cdclk;
> > +}
> > +
> >  typedef void (*vlv_dsi_dmi_quirk_func)(struct intel_dsi *intel_dsi);
> >  
> >  /*
> > diff --git a/drivers/gpu/drm/i915/display/vlv_dsi.h b/drivers/gpu/drm/i915/display/vlv_dsi.h
> > index cf9d7b82f288..5f99059b4c48 100644
> > --- a/drivers/gpu/drm/i915/display/vlv_dsi.h
> > +++ b/drivers/gpu/drm/i915/display/vlv_dsi.h
> > @@ -8,13 +8,17 @@
> >  
> >  #include <linux/types.h>
> >  
> > +#include <drm/drm_mipi_dsi.h>
> > +
> 
> Huh, why is this required? At least it's unrelated to the patch.

Sorry meant to note that in the commit msg, but forgot.

xe fails to build without this:
../drivers/gpu/drm/i915/display/vlv_dsi.h:28:42: error: return type is an incomplete type

It looks like a forward declaration is not enough for
return types of static inline functions. i915 on the other
hand builds fine.

I suppose one alternative would be to declare is as just
'int' for xe.

> 
> Other than that,
> 
> Reviewed-by: Jani Nikula <jani.nikula@intel.com>
> 
> 
> >  enum port;
> >  struct drm_i915_private;
> > +struct intel_crtc_state;
> >  struct intel_dsi;
> >  
> >  #ifdef I915
> >  void vlv_dsi_wait_for_fifo_empty(struct intel_dsi *intel_dsi, enum port port);
> >  enum mipi_dsi_pixel_format pixel_format_from_register_bits(u32 fmt);
> > +int vlv_dsi_min_cdclk(const struct intel_crtc_state *crtc_state);
> >  void vlv_dsi_init(struct drm_i915_private *dev_priv);
> >  #else
> >  static inline void vlv_dsi_wait_for_fifo_empty(struct intel_dsi *intel_dsi, enum port port)
> > @@ -24,6 +28,10 @@ static inline enum mipi_dsi_pixel_format pixel_format_from_register_bits(u32 fmt
> >  {
> >  	return 0;
> >  }
> > +static inline int vlv_dsi_min_cdclk(const struct intel_crtc_state *crtc_state)
> > +{
> > +	return 0;
> > +}
> >  static inline void vlv_dsi_init(struct drm_i915_private *dev_priv)
> >  {
> >  }
> 
> -- 
> Jani Nikula, Intel

-- 
Ville Syrjälä
Intel