[PATCH v2 6/6] drm/i915/alpm: Add debugfs for LOBF

[Hogander, Jouni]

On Fri, 2024-04-12 at 21:22 +0530, Animesh Manna wrote:
> For validation purpose add debugfs for LOBF.
> 
> Signed-off-by: Animesh Manna <animesh.manna at intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_alpm.c     | 47
> +++++++++++++++++++
>  drivers/gpu/drm/i915/display/intel_alpm.h     |  2 +
>  .../drm/i915/display/intel_display_debugfs.c  |  2 +
>  3 files changed, 51 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_alpm.c
> b/drivers/gpu/drm/i915/display/intel_alpm.c
> index ae894c85233c..21dfc06952d7 100644
> --- a/drivers/gpu/drm/i915/display/intel_alpm.c
> +++ b/drivers/gpu/drm/i915/display/intel_alpm.c
> @@ -339,3 +339,50 @@ void intel_alpm_configure(struct intel_dp
> *intel_dp)
>  {
>         lnl_alpm_configure(intel_dp);
>  }
> +
> +static int i915_edp_lobf_support_show(struct seq_file *m, void
> *data)
> +{
> +       struct intel_connector *connector = m->private;
> +       struct intel_dp *intel_dp = intel_attached_dp(connector);
> +
> +       seq_printf(m, "LOBF support: = %s",
> +                  str_yes_no(intel_dp->lobf_supported));
> +
> +       return 0;

What this debugfs is telling? Lobf may be supported by platform, but
not enabled because PSR is enabled. Saying LOBF support = no is
misleading.
 
> +}
> +
> +DEFINE_SHOW_ATTRIBUTE(i915_edp_lobf_support);
> +
> +static int i915_edp_lobf_status_show(struct seq_file *m, void *data)
> +{
> +       struct intel_connector *connector = m->private;
> +       struct intel_dp *intel_dp = intel_attached_dp(connector);
> +       const char *status;
> +
> +       if (intel_dp->lobf_enabled)

I think better option is to read it from the registers.

BR,

Jouni Högander

> +               status = "enabled";
> +       else
> +               status = "disabled";
> +
> +       seq_printf(m, "LOBF: %s\n", status);
> +
> +       return 0;
> +}
> +
> +DEFINE_SHOW_ATTRIBUTE(i915_edp_lobf_status);
> +
> +void intel_alpm_lobf_debugfs_add(struct intel_connector *connector)
> +{
> +       struct drm_i915_private *i915 = to_i915(connector->base.dev);
> +       struct dentry *root = connector->base.debugfs_entry;
> +
> +       if (DISPLAY_VER(i915) >= 20 &&
> +           connector->base.connector_type != DRM_MODE_CONNECTOR_eDP)
> +               return;
> +
> +       debugfs_create_file("i915_edp_lobf_supported", 0444, root,
> +                           connector, &i915_edp_lobf_support_fops);
> +
> +       debugfs_create_file("i915_edp_lobf_status", 0444, root,
> +                           connector, &i915_edp_lobf_status_fops);
> +}
> diff --git a/drivers/gpu/drm/i915/display/intel_alpm.h
> b/drivers/gpu/drm/i915/display/intel_alpm.h
> index c341d2c2b7f7..66e81ed8b2fb 100644
> --- a/drivers/gpu/drm/i915/display/intel_alpm.h
> +++ b/drivers/gpu/drm/i915/display/intel_alpm.h
> @@ -11,6 +11,7 @@
>  struct intel_dp;
>  struct intel_crtc_state;
>  struct drm_connector_state;
> +struct intel_connector;
>  
>  bool intel_dp_get_aux_less_alpm_status(struct intel_dp *intel_dp);
>  bool intel_alpm_compute_params(struct intel_dp *intel_dp,
> @@ -19,5 +20,6 @@ void intel_alpm_compute_lobf_config(struct intel_dp
> *intel_dp,
>                                     struct intel_crtc_state
> *crtc_state,
>                                     struct drm_connector_state
> *conn_state);
>  void intel_alpm_configure(struct intel_dp *intel_dp);
> +void intel_alpm_lobf_debugfs_add(struct intel_connector *connector);
>  
>  #endif
> diff --git a/drivers/gpu/drm/i915/display/intel_display_debugfs.c
> b/drivers/gpu/drm/i915/display/intel_display_debugfs.c
> index 0feffe8d4e45..ba1530149836 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_debugfs.c
> +++ b/drivers/gpu/drm/i915/display/intel_display_debugfs.c
> @@ -13,6 +13,7 @@
>  #include "i915_debugfs.h"
>  #include "i915_irq.h"
>  #include "i915_reg.h"
> +#include "intel_alpm.h"
>  #include "intel_crtc.h"
>  #include "intel_de.h"
>  #include "intel_crtc_state_dump.h"
> @@ -1542,6 +1543,7 @@ void intel_connector_debugfs_add(struct
> intel_connector *connector)
>         intel_drrs_connector_debugfs_add(connector);
>         intel_pps_connector_debugfs_add(connector);
>         intel_psr_connector_debugfs_add(connector);
> +       intel_alpm_lobf_debugfs_add(connector);
>  
>         if (connector_type == DRM_MODE_CONNECTOR_DisplayPort ||
>             connector_type == DRM_MODE_CONNECTOR_HDMIA ||