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

[Manna, Animesh]

> -----Original Message-----
> From: Hogander, Jouni <jouni.hogander at intel.com>
> Sent: Monday, April 15, 2024 3:44 PM
> To: Manna, Animesh <animesh.manna at intel.com>; intel-
> gfx at lists.freedesktop.org
> Cc: dri-devel at lists.freedesktop.org; Murthy, Arun R
> <arun.r.murthy at intel.com>; Nikula, Jani <jani.nikula at intel.com>
> Subject: Re: [PATCH v2 6/6] drm/i915/alpm: Add debugfs for LOBF
> 
> 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.

How about "LOBF entry criteria met = yes/no"?

> 
> > +}
> > +
> > +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.

Sure, will add.

Regards,
Animesh

> 
> 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 ||