drm/i915/dmc_wl: Allow enable_dmc_wl=3 to mean "always locked"

When debugging issues that might be related to the DMC wakelock code, it
might be useful to compare runs with the lock acquired while DC states
are enabled vs the regular case. If issues disappear with the former, it
might be a symptom of something wrong in our code. Support having this
"always locked" behavior with enable_dmc_wl=3.

Signed-off-by: Gustavo Sousa <gustavo.sousa@intel.com>
Reviewed-by: Dnyaneshwar Bhadane <dnyaneshwar.bhadane@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241219221429.109668-5-gustavo.sousa@intel.com
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>

diff --git a/drivers/gpu/drm/i915/display/intel_display_params.c b/drivers/gpu/drm/i915/display/intel_display_params.c
index f0f388f38fa7ddf26ab224b9e99d4626efafdebf..c4f1ab43fc0c864a97226e216b9178749749049a 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_display_params.c
+++ b/drivers/gpu/drm/i915/display/intel_display_params.c
@@ -130,7 +130,7 @@ intel_display_param_named_unsafe(enable_psr2_sel_fetch, bool, 0400,
 
 intel_display_param_named_unsafe(enable_dmc_wl, int, 0400,
        "Enable DMC wakelock "
-       "(-1=use per-chip default, 0=disabled, 1=enabled, 2=match any register) "
+       "(-1=use per-chip default, 0=disabled, 1=enabled, 2=match any register, 3=always locked) "
        "Default: -1");
 
 __maybe_unused

diff --git a/drivers/gpu/drm/i915/display/intel_dmc_wl.c b/drivers/gpu/drm/i915/display/intel_dmc_wl.c
index d442a150b3274b7ed449a2ae2501edcaf9ddc0d2..1bdc08e6aa4524dfe73b21038ab3e5c66c2b2bab 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_dmc_wl.c
+++ b/drivers/gpu/drm/i915/display/intel_dmc_wl.c
@@ -57,6 +57,7 @@ enum {
        ENABLE_DMC_WL_DISABLED,
        ENABLE_DMC_WL_ENABLED,
        ENABLE_DMC_WL_ANY_REGISTER,
+       ENABLE_DMC_WL_ALWAYS_LOCKED,
        ENABLE_DMC_WL_MAX,
 };
 
@@ -312,6 +313,9 @@ static void intel_dmc_wl_sanitize_param(struct intel_display *display)
        case ENABLE_DMC_WL_ANY_REGISTER:
                desc = "match any register";
                break;
+       case ENABLE_DMC_WL_ALWAYS_LOCKED:
+               desc = "always locked";
+               break;
        default:
                desc = "unknown";
                break;
@@ -332,7 +336,8 @@ void intel_dmc_wl_init(struct intel_display *display)
 
        INIT_DELAYED_WORK(&wl->work, intel_dmc_wl_work);
        spin_lock_init(&wl->lock);
-       refcount_set(&wl->refcount, 0);
+       refcount_set(&wl->refcount,
+                    display->params.enable_dmc_wl == ENABLE_DMC_WL_ALWAYS_LOCKED ? 1 : 0);
 }
 
 /* Must only be called as part of enabling dynamic DC states. */