[PATCH v6 27/28] drm/i915/dsc: Add Per connector debugfs node for DSC support/enable

[Manasi Navare]

On Mon, Oct 29, 2018 at 10:39:21PM +0200, Ville Syrjälä wrote:
> On Wed, Oct 24, 2018 at 03:28:39PM -0700, Manasi Navare wrote:
> > DSC can be supported per DP connector. This patch adds a per connector
> > debugfs node to expose DSC support capability by the kernel.
> > The same node can be used from userspace to force DSC enable.
> 
> Why is the force_dsc thing split between two patches so strangely?

This patch just defines the force_dsc and sets it through the debugfs
node. But how it configures DSC during atomic check is moved to a
separate patch. 
Would you prefer having that integrated with this patch itself?

Manasi

> 
> > 
> > v2:
> > * Use kstrtobool_from_user to avoid explicit error checking (Lyude)
> > * Rebase on drm-tip (Manasi)
> > 
> > Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
> > Cc: Ville Syrjala <ville.syrjala at linux.intel.com>
> > Cc: Anusha Srivatsa <anusha.srivatsa at intel.com>
> > Cc: Lyude Paul <lyude at redhat.com>
> > Signed-off-by: Manasi Navare <manasi.d.navare at intel.com>
> > Reviewed-by: Lyude Paul <lyude at redhat.com>
> > ---
> >  drivers/gpu/drm/i915/i915_debugfs.c | 71 ++++++++++++++++++++++++++++-
> >  drivers/gpu/drm/i915/intel_dp.c     |  1 +
> >  drivers/gpu/drm/i915/intel_drv.h    |  3 ++
> >  3 files changed, 74 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
> > index 5cadfcd03ea9..6e631f08dd4b 100644
> > --- a/drivers/gpu/drm/i915/i915_debugfs.c
> > +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> > @@ -4999,6 +4999,72 @@ static int i915_hdcp_sink_capability_show(struct seq_file *m, void *data)
> >  }
> >  DEFINE_SHOW_ATTRIBUTE(i915_hdcp_sink_capability);
> >  
> > +static int i915_dsc_support_show(struct seq_file *m, void *data)
> > +{
> > +	struct drm_connector *connector = m->private;
> > +	struct intel_encoder *encoder = intel_attached_encoder(connector);
> > +	struct intel_dp *intel_dp =
> > +		enc_to_intel_dp(&encoder->base);
> > +	struct intel_crtc *crtc;
> > +	struct intel_crtc_state *crtc_state;
> > +
> > +	crtc = to_intel_crtc(encoder->base.crtc);
> > +	crtc_state = to_intel_crtc_state(crtc->base.state);
> > +	drm_modeset_lock(&crtc->base.mutex, NULL);
> > +	seq_printf(m, "Enabled: %s\n",
> > +		   yesno(crtc_state->dsc_params.compression_enable));
> > +	seq_printf(m, "Supported: %s\n",
> > +		   yesno(drm_dp_sink_supports_dsc(intel_dp->dsc_dpcd)));
> > +	drm_modeset_unlock(&crtc->base.mutex);
> > +
> > +	return 0;
> > +}
> > +
> > +static ssize_t i915_dsc_support_write(struct file *file,
> > +				      const char __user *ubuf,
> > +				      size_t len, loff_t *offp)
> > +{
> > +	bool dsc_enable = false;
> > +	int ret;
> > +	struct drm_connector *connector =
> > +		((struct seq_file *)file->private_data)->private;
> > +	struct intel_encoder *encoder = intel_attached_encoder(connector);
> > +	struct intel_dp *intel_dp = enc_to_intel_dp(&encoder->base);
> > +
> > +	if (len == 0)
> > +		return 0;
> > +
> > +	DRM_DEBUG_DRIVER("Copied %d bytes from user to force DSC\n",
> > +			 (unsigned int)len);
> > +
> > +	ret = kstrtobool_from_user(ubuf, len, &dsc_enable);
> > +	if (ret < 0)
> > +		return ret;
> > +
> > +	DRM_DEBUG_DRIVER("Got %s for DSC Enable\n",
> > +			 (dsc_enable) ? "true" : "false");
> > +	intel_dp->force_dsc_en = dsc_enable;
> > +
> > +	*offp += len;
> > +	return len;
> > +}
> > +
> > +static int i915_dsc_support_open(struct inode *inode,
> > +				 struct file *file)
> > +{
> > +	return single_open(file, i915_dsc_support_show,
> > +			   inode->i_private);
> > +}
> > +
> > +static const struct file_operations i915_dsc_support_fops = {
> > +	.owner = THIS_MODULE,
> > +	.open = i915_dsc_support_open,
> > +	.read = seq_read,
> > +	.llseek = seq_lseek,
> > +	.release = single_release,
> > +	.write = i915_dsc_support_write
> > +};
> > +
> >  /**
> >   * i915_debugfs_connector_add - add i915 specific connector debugfs files
> >   * @connector: pointer to a registered drm_connector
> > @@ -5017,9 +5083,12 @@ int i915_debugfs_connector_add(struct drm_connector *connector)
> >  		return -ENODEV;
> >  
> >  	if (connector->connector_type == DRM_MODE_CONNECTOR_DisplayPort ||
> > -	    connector->connector_type == DRM_MODE_CONNECTOR_eDP)
> > +	    connector->connector_type == DRM_MODE_CONNECTOR_eDP) {
> >  		debugfs_create_file("i915_dpcd", S_IRUGO, root,
> >  				    connector, &i915_dpcd_fops);
> > +		debugfs_create_file("i915_dsc_support", S_IRUGO, root,
> > +				    connector, &i915_dsc_support_fops);
> > +	}
> >  
> >  	if (connector->connector_type == DRM_MODE_CONNECTOR_eDP) {
> >  		debugfs_create_file("i915_panel_timings", S_IRUGO, root,
> > diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> > index 72e6605f0ed7..0b5939992c2b 100644
> > --- a/drivers/gpu/drm/i915/intel_dp.c
> > +++ b/drivers/gpu/drm/i915/intel_dp.c
> > @@ -2287,6 +2287,7 @@ intel_dp_compute_config(struct intel_encoder *encoder,
> >  	if (adjusted_mode->flags & DRM_MODE_FLAG_DBLCLK)
> >  		return false;
> >  
> > +	DRM_DEBUG_KMS("Force DSC en = %d\n", intel_dp->force_dsc_en);
> >  	if (!intel_dp_compute_link_config(encoder, pipe_config))
> >  		return false;
> >  
> > diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> > index 4f5d17bcd54e..16bbc3768e02 100644
> > --- a/drivers/gpu/drm/i915/intel_drv.h
> > +++ b/drivers/gpu/drm/i915/intel_drv.h
> > @@ -1196,6 +1196,9 @@ struct intel_dp {
> >  
> >  	/* Displayport compliance testing */
> >  	struct intel_dp_compliance compliance;
> > +
> > +	/* Display stream compression testing */
> > +	bool force_dsc_en;
> >  };
> >  
> >  enum lspcon_vendor {
> > -- 
> > 2.18.0
> 
> -- 
> Ville Syrjälä
> Intel