FAILED: Patch "Revert "drm/i915/dsi: Do display on sequence later on icl+"" failed to apply to 4.19-stable tree

[Sasha Levin]

The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable at vger.kernel.org>.

Thanks,
Sasha

------------------ original commit in Linus's tree ------------------

>From dc524d05974f615b145404191fcf91b478950499 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= <ville.syrjala at linux.intel.com>
Date: Tue, 16 Jan 2024 23:08:21 +0200
Subject: [PATCH] Revert "drm/i915/dsi: Do display on sequence later on icl+"
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This reverts commit 88b065943cb583e890324d618e8d4b23460d51a3.

Lenovo 82TQ is unhappy if we do the display on sequence this
late. The display output shows severe corruption.

It's unclear if this is a failure on our part (perhaps
something to do with sending commands in LP mode after HS
/video mode transmission has been started? Though the backlight
on command at least seems to work) or simply that there are
some commands in the sequence that are needed to be done
earlier (eg. could be some DSC init stuff?). If the latter
then I don't think the current Windows code would work
either, but maybe this was originally tested with an older
driver, who knows.

Root causing this fully would likely require a lot of
experimentation which isn't really feasible without direct
access to the machine, so let's just accept failure and
go back to the original sequence.

Cc: stable at vger.kernel.org
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/10071
Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240116210821.30194-1-ville.syrjala@linux.intel.com
Acked-by: Jani Nikula <jani.nikula at intel.com>
---
 drivers/gpu/drm/i915/display/icl_dsi.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/icl_dsi.c b/drivers/gpu/drm/i915/display/icl_dsi.c
index ac456a2275dba..eda4a8b885904 100644
--- a/drivers/gpu/drm/i915/display/icl_dsi.c
+++ b/drivers/gpu/drm/i915/display/icl_dsi.c
@@ -1155,6 +1155,7 @@ static void gen11_dsi_powerup_panel(struct intel_encoder *encoder)
 	}
 
 	intel_dsi_vbt_exec_sequence(intel_dsi, MIPI_SEQ_INIT_OTP);
+	intel_dsi_vbt_exec_sequence(intel_dsi, MIPI_SEQ_DISPLAY_ON);
 
 	/* ensure all panel commands dispatched before enabling transcoder */
 	wait_for_cmds_dispatched_to_panel(encoder);
@@ -1255,8 +1256,6 @@ static void gen11_dsi_enable(struct intel_atomic_state *state,
 	/* step6d: enable dsi transcoder */
 	gen11_dsi_enable_transcoder(encoder);
 
-	intel_dsi_vbt_exec_sequence(intel_dsi, MIPI_SEQ_DISPLAY_ON);
-
 	/* step7: enable backlight */
 	intel_backlight_enable(crtc_state, conn_state);
 	intel_dsi_vbt_exec_sequence(intel_dsi, MIPI_SEQ_BACKLIGHT_ON);
-- 
2.43.0