[Intel-gfx] [PATCH 7/8] drm/i915/dsc: Add debugfs entry to validate DSC fractional bpp

[Kandpal, Suraj]

> Subject: [PATCH 7/8] drm/i915/dsc: Add debugfs entry to validate DSC fractional
> bpp
> 
> From: Swati Sharma <swati2.sharma at intel.com>
> 
> DSC_Sink_BPP_Precision entry is added to i915_dsc_fec_support_show to
> depict sink's precision.
> Also, new debugfs entry is created to enforce fractional bpp.
> If Force_DSC_Fractional_BPP_en is set then while iterating over output bpp
> with fractional step size we will continue if output_bpp is computed as integer.
> With this approach, we will be able to validate DSC with fractional bpp.
> 
> Signed-off-by: Swati Sharma <swati2.sharma at intel.com>
> Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal at intel.com>
> ---
>  .../drm/i915/display/intel_display_debugfs.c  | 82 +++++++++++++++++++
>  .../drm/i915/display/intel_display_types.h    |  1 +
>  2 files changed, 83 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display_debugfs.c
> b/drivers/gpu/drm/i915/display/intel_display_debugfs.c
> index f05b52381a83..d1b202e14e5f 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_debugfs.c
> +++ b/drivers/gpu/drm/i915/display/intel_display_debugfs.c
> @@ -1244,6 +1244,8 @@ static int i915_dsc_fec_support_show(struct seq_file
> *m, void *data)
> 
> DP_DSC_YCbCr420_Native)),
> 
> str_yes_no(drm_dp_dsc_sink_supports_format(intel_dp->dsc_dpcd,
> 
> DP_DSC_YCbCr444)));
> +		seq_printf(m, "DSC_Sink_BPP_Precision: %d\n",
> +			   drm_dp_dsc_sink_bpp_incr(intel_dp->dsc_dpcd));
>  		seq_printf(m, "Force_DSC_Enable: %s\n",
>  			   str_yes_no(intel_dp->force_dsc_en));
>  		if (!intel_dp_is_edp(intel_dp))
> @@ -1436,6 +1438,83 @@ static const struct file_operations
> i915_dsc_output_format_fops = {
>  	.write = i915_dsc_output_format_write
>  };
> 
> +static int i915_dsc_fractional_bpp_show(struct seq_file *m, void *data)
> +{
> +	struct drm_connector *connector = m->private;
> +	struct drm_device *dev = connector->dev;
> +	struct drm_crtc *crtc;
> +	struct intel_dp *intel_dp;
> +	struct intel_encoder *encoder =
> intel_attached_encoder(to_intel_connector(connector));
> +	int ret;
> +
> +	if (!encoder)
> +		return -ENODEV;
> +
> +	ret = drm_modeset_lock_single_interruptible(&dev-
> >mode_config.connection_mutex);
> +	if (ret)
> +		return ret;
> +
> +	crtc = connector->state->crtc;
> +	if (connector->status != connector_status_connected || !crtc) {
> +		ret = -ENODEV;
> +		goto out;
> +	}
> +
> +	intel_dp = intel_attached_dp(to_intel_connector(connector));
> +	seq_printf(m, "Force_DSC_Fractional_BPP_Enable: %s\n",
> +		   str_yes_no(intel_dp->force_dsc_fractional_bpp_en));
> +
> +out:	drm_modeset_unlock(&dev->mode_config.connection_mutex);
> +

The above function should be on a new line and the extra new line can be removed
return and modeset_unlock

With that fixed
LGTM.
Reviewed-by: Suraj Kandpal <suraj.kandpal at intel.com>

> +	return ret;
> +}
> +
> +static ssize_t i915_dsc_fractional_bpp_write(struct file *file,
> +					     const char __user *ubuf,
> +					     size_t len, loff_t *offp)
> +{
> +	struct drm_connector *connector =
> +		((struct seq_file *)file->private_data)->private;
> +	struct intel_encoder *encoder =
> intel_attached_encoder(to_intel_connector(connector));
> +	struct drm_i915_private *i915 = to_i915(encoder->base.dev);
> +	struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
> +	bool dsc_fractional_bpp_enable = false;
> +	int ret;
> +
> +	if (len == 0)
> +		return 0;
> +
> +	drm_dbg(&i915->drm,
> +		"Copied %zu bytes from user to force fractional bpp for
> DSC\n", len);
> +
> +	ret = kstrtobool_from_user(ubuf, len, &dsc_fractional_bpp_enable);
> +	if (ret < 0)
> +		return ret;
> +
> +	drm_dbg(&i915->drm, "Got %s for DSC Fractional BPP Enable\n",
> +		(dsc_fractional_bpp_enable) ? "true" : "false");
> +	intel_dp->force_dsc_fractional_bpp_en = dsc_fractional_bpp_enable;
> +
> +	*offp += len;
> +
> +	return len;
> +}
> +
> +static int i915_dsc_fractional_bpp_open(struct inode *inode,
> +					struct file *file)
> +{
> +	return single_open(file, i915_dsc_fractional_bpp_show,
> +inode->i_private); }
> +
> +static const struct file_operations i915_dsc_fractional_bpp_fops = {
> +	.owner = THIS_MODULE,
> +	.open = i915_dsc_fractional_bpp_open,
> +	.read = seq_read,
> +	.llseek = seq_lseek,
> +	.release = single_release,
> +	.write = i915_dsc_fractional_bpp_write };
> +
>  /*
>   * Returns the Current CRTC's bpc.
>   * Example usage: cat /sys/kernel/debug/dri/0/crtc-0/i915_current_bpc
> @@ -1513,6 +1592,9 @@ void intel_connector_debugfs_add(struct
> intel_connector *intel_connector)
> 
>  		debugfs_create_file("i915_dsc_output_format", 0644, root,
>  				    connector, &i915_dsc_output_format_fops);
> +
> +		debugfs_create_file("i915_dsc_fractional_bpp", 0644, root,
> +				    connector, &i915_dsc_fractional_bpp_fops);
>  	}
> 
>  	if (connector->connector_type == DRM_MODE_CONNECTOR_DSI ||
> diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h
> b/drivers/gpu/drm/i915/display/intel_display_types.h
> index 9eb7b8912076..6e76f1274b0c 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> @@ -1797,6 +1797,7 @@ struct intel_dp {
>  	/* Display stream compression testing */
>  	bool force_dsc_en;
>  	int force_dsc_output_format;
> +	bool force_dsc_fractional_bpp_en;
>  	int force_dsc_bpc;
> 
>  	bool hobl_failed;
> --
> 2.25.1