[J/OEM-5.14] [PATCH 09/11] drm/i915/display/adlp: Optimize PSR2 power-savings in corner cases

Kai-Heng Feng kai.heng.feng at canonical.com
Mon Jun 13 07:00:07 UTC 2022

From: José Roberto de Souza <jose.souza at intel.com>

BugLink: https://bugs.launchpad.net/bugs/1978252

The Wa_14014971508 is required to fix scanout when a feature that i915
do not support is enabled and this feature is not planned to be enabled
for adlp.

Keeping this workaround enabled can badly hurt power-savings when
a full frame fetch is required(see psr2_sel_fetch_plane_state_supported()
and psr2_sel_fetch_pipe_state_supported()).

Here a example that could badly hurt power-savings, userspace does
a page flip to a rotated plane, so CONTINUOS_FULL_FRAME set.
But then for a whole 30 seconds nothing in the screen requires updates
but because CONTINUOS_FULL_FRAME is set, it will not go into DC5/DC6.

Reverting Wa_14014971508 fixes that, as only a single frame will be
sent and then display can go to DC5/DC6 for those 30 seconds of

BSpec: 54369
Cc: Gwan-gyeong Mun <gwan-gyeong.mun at intel.com>
Signed-off-by: José Roberto de Souza <jose.souza at intel.com>
Reviewed-by: Gwan-gyeong Mun <gwan-gyeong.mun at intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210930001409.254817-6-jose.souza@intel.com
(backported from commit 1163649a047995c77527023f192d00ae1971965b)
Signed-off-by: Kai-Heng Feng <kai.heng.feng at canonical.com>
 drivers/gpu/drm/i915/display/intel_psr.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_psr.c b/drivers/gpu/drm/i915/display/intel_psr.c
index 2cedb7e88a176..255142ebe213d 100644
--- a/drivers/gpu/drm/i915/display/intel_psr.c
+++ b/drivers/gpu/drm/i915/display/intel_psr.c
@@ -1496,11 +1496,11 @@ static void psr2_man_trk_ctl_calc(struct intel_crtc_state *crtc_state,
 	u32 val = PSR2_MAN_TRK_CTL_ENABLE;
 	if (full_update) {
-		if (IS_ALDERLAKE_P(dev_priv))
-		else
+		/*
+		 * Not applying Wa_14014971508:adlp as we do not support the
+		 * feature that requires this workaround.
+		 */
+		val |= man_trk_ctl_single_full_frame_bit_get(dev_priv);
 		goto exit;

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