[PATCH 13/19] drm/i915/psr: Write the PR config DPCDs in burst mode

Ankit Nautiyal
2026-03-30T04:22:37Z

Replace the consecutive single-byte writes to PANEL_REPLAY_CONFIG and
CONFIG2 with one drm_dp_dpcd_write() burst starting at PANEL_REPLAY_CONFIG,
reducing AUX transactions.

v2: Drop extra conditions, and optimize variables. (Ville)

Suggested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
---
drivers/gpu/drm/i915/display/intel_psr.c | 29 ++++++++++++++----------
1 file changed, 17 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_psr.c b/drivers/gpu/drm/i915/display/intel_psr.c
index 2f1b48cd8efd..ca054135ca30 100644
--- a/drivers/gpu/drm/i915/display/intel_psr.c
+++ b/drivers/gpu/drm/i915/display/intel_psr.c
@@ -782,27 +782,32 @@ static bool psr2_su_region_et_valid(struct intel_connector *connector, bool pane
static void _panel_replay_enable_sink(struct intel_dp *intel_dp,
const struct intel_crtc_state *crtc_state)
{
- u8 val = DP_PANEL_REPLAY_ENABLE |
- DP_PANEL_REPLAY_VSC_SDP_CRC_EN |
- DP_PANEL_REPLAY_UNRECOVERABLE_ERROR_EN |
- DP_PANEL_REPLAY_RFB_STORAGE_ERROR_EN |
- DP_PANEL_REPLAY_ACTIVE_FRAME_CRC_ERROR_EN;
- u8 panel_replay_config2 = DP_PANEL_REPLAY_CRC_VERIFICATION;
+ struct intel_display *display = to_intel_display(intel_dp);
+ u8 panel_replay_config[2];
+ int ret;
+
+ panel_replay_config[0] = DP_PANEL_REPLAY_ENABLE |
+ DP_PANEL_REPLAY_VSC_SDP_CRC_EN |
+ DP_PANEL_REPLAY_UNRECOVERABLE_ERROR_EN |
+ DP_PANEL_REPLAY_RFB_STORAGE_ERROR_EN |
+ DP_PANEL_REPLAY_ACTIVE_FRAME_CRC_ERROR_EN;
+ panel_replay_config[1] = DP_PANEL_REPLAY_CRC_VERIFICATION;

if (crtc_state->has_sel_update)
- val |= DP_PANEL_REPLAY_SU_ENABLE;
+ panel_replay_config[0] |= DP_PANEL_REPLAY_SU_ENABLE;

if (crtc_state->enable_psr2_su_region_et)
- val |= DP_PANEL_REPLAY_ENABLE_SU_REGION_ET;
+ panel_replay_config[0] |= DP_PANEL_REPLAY_ENABLE_SU_REGION_ET;

if (crtc_state->req_psr2_sdp_prior_scanline)
- panel_replay_config2 |=
+ panel_replay_config[1] |=
DP_PANEL_REPLAY_SU_REGION_SCANLINE_CAPTURE;

- drm_dp_dpcd_writeb(&intel_dp->aux, PANEL_REPLAY_CONFIG, val);
+ ret = drm_dp_dpcd_write(&intel_dp->aux, PANEL_REPLAY_CONFIG,
+ panel_replay_config, sizeof(panel_replay_config));

- drm_dp_dpcd_writeb(&intel_dp->aux, PANEL_REPLAY_CONFIG2,
- panel_replay_config2);
+ if (ret != sizeof(panel_replay_config))
+ drm_dbg_kms(display->drm, "Failed to write Panel Replay Configs\n");
}

static void _psr_enable_sink(struct intel_dp *intel_dp,
--
2.45.2