[Intel-gfx] [PATCH v2 2/2] drm/i915: Don't advertise modes that exceed the max plane size

Sean Paul sean at poorly.run
Wed Sep 18 20:21:06 UTC 2019


On Wed, Sep 18, 2019 at 07:02:18PM +0300, Ville Syrjälä wrote:
> On Wed, Sep 18, 2019 at 11:24:09AM -0400, Sean Paul wrote:
> > On Wed, Sep 18, 2019 at 06:07:07PM +0300, Ville Syrjala wrote:
> > > From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > > 
> > > Modern platforms allow the transcoders hdisplay/vdisplay to exceed the
> > > planes' max resolution. This has the nasty implication that modes on the
> > > connectors' mode list may not be usable when the user asks for a
> > > fullscreen plane. Seeing as that is the most common use case it seems
> > > prudent to filter out modes that don't allow for fullscreen planes to
> > > be enabled.
> > > 
> > > Let's do that in the connetor .mode_valid() hook so that normally
> > > such modes are kept hidden but the user is still able to forcibly
> > > specify such a mode if they know they don't need fullscreen planes.
> > > 
> > > This is in line with ealier policies regarding certain clock limits.
> > > The idea is to prevent the casual user from encountering a mode that
> > > would fail under typical conditions, but allow the expert user to
> > > force things if they so wish.
> > 
> > Isn't this exactly what atomic_check is for? Why not just add a debug message in
> > get_max_plane_size to leave a breadcrumb?
> 
> There's already a debug message. Won't really help when the screen fails
> to light up automagically on account of the preferred mode being too
> big.

That's not the kernel's fault, why are we working around it at this level? There
are lots of reasons beyond max plane size that can cause a modeset to fail. If
userspace doesn't already have the smarts to fallback to a lower resolution on
modeset failure, we should fix it or just ¯\_(ツ)_/¯

Sean

> 
> > 
> > Sean
> > 
> > > 
> > > Maybe in the future we should consider automagically using two
> > > planes when one can't cover the entire screen? Wouldn't be a
> > > great match for the current uapi with explicit planes though,
> > > but I guess no worse than using two pipes (which we apparently
> > > have to in the future anyway). Either that or we'd have to
> > > teach userspace to do it for us.
> > > 
> > > v2: Fix icl+ max plane heigth (Manasi)
> > > 
> > > Cc: Manasi Navare <manasi.d.navare at intel.com>
> > > Cc: Leho Kraav <leho at kraav.com>
> > > Cc: Sean Paul <sean at poorly.run>
> > > Cc: José Roberto de Souza <jose.souza at intel.com>
> > > Reviewed-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> > > Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > > ---
> > >  drivers/gpu/drm/i915/display/intel_display.c | 36 ++++++++++++++++++++
> > >  drivers/gpu/drm/i915/display/intel_display.h |  4 +++
> > >  drivers/gpu/drm/i915/display/intel_dp.c      |  2 +-
> > >  drivers/gpu/drm/i915/display/intel_dsi.c     |  3 +-
> > >  drivers/gpu/drm/i915/display/intel_hdmi.c    |  4 ++-
> > >  5 files changed, 46 insertions(+), 3 deletions(-)
> > > 
> > > diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> > > index f5e65e052d91..0147e4ae3622 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_display.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_display.c
> > > @@ -15753,6 +15753,7 @@ intel_mode_valid(struct drm_device *dev,
> > >  			   DRM_MODE_FLAG_CLKDIV2))
> > >  		return MODE_BAD;
> > >  
> > > +	/* Transcoder timing limits */
> > >  	if (INTEL_GEN(dev_priv) >= 11) {
> > >  		hdisplay_max = 16384;
> > >  		vdisplay_max = 8192;
> > > @@ -15791,6 +15792,41 @@ intel_mode_valid(struct drm_device *dev,
> > >  	return MODE_OK;
> > >  }
> > >  
> > > +enum drm_mode_status
> > > +intel_mode_valid_max_plane_size(struct drm_i915_private *dev_priv,
> > > +				const struct drm_display_mode *mode)
> > > +{
> > > +	int plane_width_max, plane_height_max;
> > > +
> > > +	/*
> > > +	 * intel_mode_valid() should be
> > > +	 * sufficient on older platforms.
> > > +	 */
> > > +	if (INTEL_GEN(dev_priv) < 9)
> > > +		return MODE_OK;
> > > +
> > > +	/*
> > > +	 * Most people will probably want a fullscreen
> > > +	 * plane so let's not advertize modes that are
> > > +	 * too big for that.
> > > +	 */
> > > +	if (INTEL_GEN(dev_priv) >= 11) {
> > > +		plane_width_max = 5120;
> > > +		plane_height_max = 4320;
> > > +	} else {
> > > +		plane_width_max = 5120;
> > > +		plane_height_max = 4096;
> > > +	}
> > > +
> > > +	if (mode->hdisplay > plane_width_max)
> > > +		return MODE_H_ILLEGAL;
> > > +
> > > +	if (mode->vdisplay > plane_height_max)
> > > +		return MODE_V_ILLEGAL;
> > > +
> > > +	return MODE_OK;
> > > +}
> > > +
> > >  static const struct drm_mode_config_funcs intel_mode_funcs = {
> > >  	.fb_create = intel_user_framebuffer_create,
> > >  	.get_format_info = intel_get_format_info,
> > > diff --git a/drivers/gpu/drm/i915/display/intel_display.h b/drivers/gpu/drm/i915/display/intel_display.h
> > > index 66330fcb10d4..b1ae0e59c715 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_display.h
> > > +++ b/drivers/gpu/drm/i915/display/intel_display.h
> > > @@ -32,6 +32,7 @@ enum link_m_n_set;
> > >  struct dpll;
> > >  struct drm_connector;
> > >  struct drm_device;
> > > +struct drm_display_mode;
> > >  struct drm_encoder;
> > >  struct drm_file;
> > >  struct drm_format_info;
> > > @@ -448,6 +449,9 @@ void lpt_disable_clkout_dp(struct drm_i915_private *dev_priv);
> > >  u32 intel_plane_fb_max_stride(struct drm_i915_private *dev_priv,
> > >  			      u32 pixel_format, u64 modifier);
> > >  bool intel_plane_can_remap(const struct intel_plane_state *plane_state);
> > > +enum drm_mode_status
> > > +intel_mode_valid_max_plane_size(struct drm_i915_private *dev_priv,
> > > +				const struct drm_display_mode *mode);
> > >  enum phy intel_port_to_phy(struct drm_i915_private *i915, enum port port);
> > >  
> > >  void intel_plane_destroy(struct drm_plane *plane);
> > > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> > > index d09133a958e1..ccaf9f00b747 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_dp.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> > > @@ -562,7 +562,7 @@ intel_dp_mode_valid(struct drm_connector *connector,
> > >  	if (mode->flags & DRM_MODE_FLAG_DBLCLK)
> > >  		return MODE_H_ILLEGAL;
> > >  
> > > -	return MODE_OK;
> > > +	return intel_mode_valid_max_plane_size(dev_priv, mode);
> > >  }
> > >  
> > >  u32 intel_dp_pack_aux(const u8 *src, int src_bytes)
> > > diff --git a/drivers/gpu/drm/i915/display/intel_dsi.c b/drivers/gpu/drm/i915/display/intel_dsi.c
> > > index 5fec02aceaed..a2a937109a5a 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_dsi.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_dsi.c
> > > @@ -55,6 +55,7 @@ int intel_dsi_get_modes(struct drm_connector *connector)
> > >  enum drm_mode_status intel_dsi_mode_valid(struct drm_connector *connector,
> > >  					  struct drm_display_mode *mode)
> > >  {
> > > +	struct drm_i915_private *dev_priv = to_i915(connector->dev);
> > >  	struct intel_connector *intel_connector = to_intel_connector(connector);
> > >  	const struct drm_display_mode *fixed_mode = intel_connector->panel.fixed_mode;
> > >  	int max_dotclk = to_i915(connector->dev)->max_dotclk_freq;
> > > @@ -73,7 +74,7 @@ enum drm_mode_status intel_dsi_mode_valid(struct drm_connector *connector,
> > >  			return MODE_CLOCK_HIGH;
> > >  	}
> > >  
> > > -	return MODE_OK;
> > > +	return intel_mode_valid_max_plane_size(dev_priv, mode);
> > >  }
> > >  
> > >  struct intel_dsi_host *intel_dsi_host_init(struct intel_dsi *intel_dsi,
> > > diff --git a/drivers/gpu/drm/i915/display/intel_hdmi.c b/drivers/gpu/drm/i915/display/intel_hdmi.c
> > > index c500fc9154c8..dbc686515dce 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_hdmi.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_hdmi.c
> > > @@ -2188,8 +2188,10 @@ intel_hdmi_mode_valid(struct drm_connector *connector,
> > >  			status = hdmi_port_clock_valid(hdmi, clock * 5 / 4,
> > >  						       true, force_dvi);
> > >  	}
> > > +	if (status != MODE_OK)
> > > +		return status;
> > >  
> > > -	return status;
> > > +	return intel_mode_valid_max_plane_size(dev_priv, mode);
> > >  }
> > >  
> > >  static bool hdmi_deep_color_possible(const struct intel_crtc_state *crtc_state,
> > > -- 
> > > 2.21.0
> > > 
> > 
> > -- 
> > Sean Paul, Software Engineer, Google / Chromium OS
> 
> -- 
> Ville Syrjälä
> Intel

-- 
Sean Paul, Software Engineer, Google / Chromium OS


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