diff mbox series

[1/1,OEM-6.0/OEM-6.1] drm/i915/psr: Add continuous full frame bit together with single

Message ID 20230117090801.601978-2-chris.chiu@canonical.com
State New
Headers show
Series Fix flicker display problem on some panels which support PSR2 | expand

Commit Message

Chris Chiu Jan. 17, 2023, 9:08 a.m. UTC 
From: Jouni Högander <jouni.hogander@intel.com>

BugLink: https://bugs.launchpad.net/bugs/2002968

Currently we are observing occasionally display flickering or complete
freeze. This is narrowed down to be caused by single full frame update
(SFF).

SFF bit after it's written gets cleared by HW in subsequent vblank
i.e. when the update is sent to the panel. SFF bit is required to be
written together with partial frame update (PFU) bit. After the SFF
bit gets cleared by the HW psr2 man trk ctl register still contains
PFU bit. If there is subsequent update for any reason we will end up
having selective update/fetch configuration where start line is 0 and
end line is 0. Also selective fetch configuration for the planes is
not properly performed. This seems to be causing problems with some
panels.

Using CFF without SFF doesn't work either because it may happen that
psr2 man track ctl register is overwritten by next update before
vblank triggers sending the update. This is causing problems to
psr_invalidate/flush. Using CFF and SFF together solves the problems
as SFF is cleared only by HW in subsequent vblank and the update gets
sent.

Fix the flickering/freeze issue by keeping CFF bit as set when PSR2 is
enabled unless there is a properly configured selective update via
atomic commit.

v2:
 - Improve commit message and comments
 - No functional changes

This is also workaround for HSD 14014971508

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: José Roberto de Souza <jose.souza@intel.com>
Cc: Mika Kahola <mika.kahola@intel.com>

Reported-by: Lee Shawn C <shawn.c.lee@intel.com>
Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
Tested-by: Lee Shawn C <shawn.c.lee@intel.com>
Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221201072308.1905679-1-jouni.hogander@intel.com
(backported from commit 084aab04cc60e5eab32287d0483c33e12c92da87
linux-next)
[Chris: fix the cherry-pick failure due to the mismatched work around
name in the comment description]
Signed-off-by: Chris Chiu <chris.chiu@canonical.com>
---
 drivers/gpu/drm/i915/display/intel_psr.c | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)
diff mbox series

Patch

diff --git a/drivers/gpu/drm/i915/display/intel_psr.c b/drivers/gpu/drm/i915/display/intel_psr.c
index fbe777e02ea7..e27e15e58062 100644
--- a/drivers/gpu/drm/i915/display/intel_psr.c
+++ b/drivers/gpu/drm/i915/display/intel_psr.c
@@ -1485,7 +1485,8 @@  static void psr_force_hw_tracking_exit(struct intel_dp *intel_dp)
 			       PSR2_MAN_TRK_CTL(intel_dp->psr.transcoder),
 			       man_trk_ctl_enable_bit_get(dev_priv) |
 			       man_trk_ctl_partial_frame_bit_get(dev_priv) |
-			       man_trk_ctl_single_full_frame_bit_get(dev_priv));
+			       man_trk_ctl_single_full_frame_bit_get(dev_priv) |
+			       man_trk_ctl_continuos_full_frame(dev_priv));
 
 	/*
 	 * Display WA #0884: skl+
@@ -1599,11 +1600,8 @@  static void psr2_man_trk_ctl_calc(struct intel_crtc_state *crtc_state,
 	val |= man_trk_ctl_partial_frame_bit_get(dev_priv);
 
 	if (full_update) {
-		/*
-		 * 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);
+		val |= man_trk_ctl_continuos_full_frame(dev_priv);
 		goto exit;
 	}
 
@@ -2282,12 +2280,15 @@  static void _psr_flush_handle(struct intel_dp *intel_dp)
 			/* can we turn CFF off? */
 			if (intel_dp->psr.busy_frontbuffer_bits == 0) {
 				u32 val = man_trk_ctl_enable_bit_get(dev_priv) |
-					  man_trk_ctl_partial_frame_bit_get(dev_priv) |
-					  man_trk_ctl_single_full_frame_bit_get(dev_priv);
+					man_trk_ctl_partial_frame_bit_get(dev_priv) |
+					man_trk_ctl_single_full_frame_bit_get(dev_priv) |
+					man_trk_ctl_continuos_full_frame(dev_priv);
 
 				/*
-				 * turn continuous full frame off and do a single
-				 * full frame
+				 * Set psr2_sel_fetch_cff_enabled as false to allow selective
+				 * updates. Still keep cff bit enabled as we don't have proper
+				 * SU configuration in case update is sent for any reason after
+				 * sff bit gets cleared by the HW on next vblank.
 				 */
 				intel_de_write(dev_priv, PSR2_MAN_TRK_CTL(intel_dp->psr.transcoder),
 					       val);