[PATCH v3 3/4] drm/i915/display: add module parameter to enable DMC wakelock

[Luca Coelho]

On Thu, 2024-03-21 at 08:08 +0000, Shankar, Uma wrote:
> 
> > -----Original Message-----
> > From: Coelho, Luciano <luciano.coelho at intel.com>
> > Sent: Monday, March 18, 2024 7:08 PM
> > To: intel-gfx at lists.freedesktop.org
> > Cc: intel-xe at lists.freedesktop.org; Shankar, Uma <uma.shankar at intel.com>;
> > ville.syrjala at linux.intel.com; Nikula, Jani <jani.nikula at intel.com>
> > Subject: [PATCH v3 3/4] drm/i915/display: add module parameter to enable DMC
> > wakelock
> > 
> > This feature should be disabled by default until properly tested and mature.  Add
> > a module parameter to enable the feature for testing, while keeping it disabled by
> > default for now.
> > 
> > Signed-off-by: Luca Coelho <luciano.coelho at intel.com>
> > ---
> >  drivers/gpu/drm/i915/display/intel_display_params.c |  5 +++++
> > drivers/gpu/drm/i915/display/intel_display_params.h |  1 +
> >  drivers/gpu/drm/i915/display/intel_dmc_wl.c         | 12 ++++++++----
> >  3 files changed, 14 insertions(+), 4 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/display/intel_display_params.c
> > b/drivers/gpu/drm/i915/display/intel_display_params.c
> > index 11e03cfb774d..f40b223cc8a1 100644
> > --- a/drivers/gpu/drm/i915/display/intel_display_params.c
> > +++ b/drivers/gpu/drm/i915/display/intel_display_params.c
> > @@ -116,6 +116,11 @@
> > intel_display_param_named_unsafe(enable_psr2_sel_fetch, bool, 0400,
> >  	"(0=disabled, 1=enabled) "
> >  	"Default: 1");
> > 
> > +intel_display_param_named_unsafe(enable_dmc_wl, bool, 0400,
> > +	"Enable DMC wakelock "
> > +	"(0=disabled, 1=enabled) "
> > +	"Default: 0");
> > +
> >  __maybe_unused
> >  static void _param_print_bool(struct drm_printer *p, const char *driver_name,
> >  			      const char *name, bool val)
> > diff --git a/drivers/gpu/drm/i915/display/intel_display_params.h
> > b/drivers/gpu/drm/i915/display/intel_display_params.h
> > index 6206cc51df04..bf8dbbdb20a1 100644
> > --- a/drivers/gpu/drm/i915/display/intel_display_params.h
> > +++ b/drivers/gpu/drm/i915/display/intel_display_params.h
> > @@ -46,6 +46,7 @@ struct drm_i915_private;
> >  	param(int, enable_psr, -1, 0600) \
> >  	param(bool, psr_safest_params, false, 0400) \
> >  	param(bool, enable_psr2_sel_fetch, true, 0400) \
> > +	param(bool, enable_dmc_wl, false, 0400) \
> > 
> >  #define MEMBER(T, member, ...) T member;  struct intel_display_params { diff --
> > git a/drivers/gpu/drm/i915/display/intel_dmc_wl.c
> > b/drivers/gpu/drm/i915/display/intel_dmc_wl.c
> > index 7c991e22c616..84d054bcb2c1 100644
> > --- a/drivers/gpu/drm/i915/display/intel_dmc_wl.c
> > +++ b/drivers/gpu/drm/i915/display/intel_dmc_wl.c
> > @@ -120,7 +120,8 @@ void intel_dmc_wl_enable(struct drm_i915_private
> > *i915)
> >  	struct intel_dmc_wl *wl = &i915->display.wl;
> >  	unsigned long flags;
> > 
> > -	if (DISPLAY_VER(i915) < 20)
> > +	if (!i915->display.params.enable_dmc_wl ||
> > +	    DISPLAY_VER(i915) < 20)
> 
> Extend this check to init as well. Else it looks ok to protect under a module parameter.
> Reviewed-by: Uma Shankar <uma.shankar at intel.com>

Done.  I now added the module param check to the supported() helper
function, so it will be checked everywhere.

Thanks for the r-b.

--
Cheers,
Luca.