Re: [PATCH v4 04/13] drm/i915/display: Add DC3CO DC_STATE enable/disable support

[Dibin Moolakadan Subrahmanian]

On 01-06-2026 11:12, Manna, Animesh wrote:

-----Original Message-----
From: Dibin Moolakadan Subrahmanian
<dibin.moolakadan.subrahman...@intel.com>
Sent: Wednesday, May 27, 2026 12:48 AM
To: intel-gfx@lists.freedesktop.org; intel...@lists.freedesktop.org
Cc: Manna, Animesh <animesh.ma...@intel.com>; Shankar, Uma
<uma.shan...@intel.com>
Subject: [PATCH v4 04/13] drm/i915/display: Add DC3CO DC_STATE
enable/disable support

Add DC3CO handling to the dc_off power well sequencing and disable the
DMC wakelock when exiting DC3CO.

BSpec: 75253
Signed-off-by: Dibin Moolakadan Subrahmanian
<dibin.moolakadan.subrahman...@intel.com>
Reviewed-by: Uma Shankar <uma.shan...@intel.com>
---
  .../drm/i915/display/intel_display_power_well.c  | 16 +++++++++++++++-
  1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/display/intel_display_power_well.c
b/drivers/gpu/drm/i915/display/intel_display_power_well.c
index 611f784d8a7a..3ea080d0e21e 100644
--- a/drivers/gpu/drm/i915/display/intel_display_power_well.c
+++ b/drivers/gpu/drm/i915/display/intel_display_power_well.c
@@ -866,6 +866,13 @@ void gen9_set_dc_state(struct intel_display *display,
u32 state)
        power_domains->dc_state = val & mask;
  }

+static void xe3lpd_enable_dc3co(struct intel_display *display) {

Better to add a assert_can_enable_dc3co() which is followed for other dc-state 
programming.

Thanks, I'll  add this check in the next revision.

Regards,
Animesh

+       drm_dbg_kms(display->drm, "Enabling DC3CO\n");
+       intel_dmc_wl_enable(display, DC_STATE_EN_UPTO_DC3CO);
+       gen9_set_dc_state(display, DC_STATE_EN_UPTO_DC3CO); }
+
  static void assert_can_enable_dc5(struct intel_display *display)  {
        enum i915_power_well_id high_pg;
@@ -1054,9 +1061,13 @@ void gen9_disable_dc_states(struct intel_display
*display)
        }

        if (old_state == DC_STATE_EN_UPTO_DC5 ||
-           old_state == DC_STATE_EN_UPTO_DC6)
+           old_state == DC_STATE_EN_UPTO_DC6 ||
+           old_state == DC_STATE_EN_UPTO_DC3CO)
                intel_dmc_wl_disable(display);

+       if (old_state == DC_STATE_EN_UPTO_DC3CO)
+               return;
+
        intel_cdclk_get_cdclk(display, &cdclk_config);
        /* Can't read out voltage_level so can't use intel_cdclk_changed() */
        drm_WARN_ON(display->drm,
@@ -1092,6 +1103,9 @@ static void gen9_dc_off_power_well_disable(struct
intel_display *display,
                return;

        switch (power_domains->target_dc_state) {
+       case DC_STATE_EN_UPTO_DC3CO:
+               xe3lpd_enable_dc3co(display);
+               break;
        case DC_STATE_EN_UPTO_DC6:
                skl_enable_dc6(display);
                break;
--
2.43.0