FAILED: patch "[PATCH] drm/i915/ddi: Fix HDMI port width programming in DDI_BUF_CTL" failed to apply to 6.6-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 6.6-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@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x 166ce267ae3f96e439d8ccc838e8ec4d8b4dab73
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2025022456-vintage-hunter-6136@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

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

From 166ce267ae3f96e439d8ccc838e8ec4d8b4dab73 Mon Sep 17 00:00:00 2001
From: Imre Deak <imre.deak@intel.com>
Date: Fri, 14 Feb 2025 16:19:52 +0200
Subject: [PATCH] drm/i915/ddi: Fix HDMI port width programming in DDI_BUF_CTL

Fix the port width programming in the DDI_BUF_CTL register on MTLP+,
where this had an off-by-one error.

Cc: <stable@vger.kernel.org> # v6.5+
Fixes: b66a8abaa48a ("drm/i915/display/mtl: Fill port width in DDI_BUF_/TRANS_DDI_FUNC_/PORT_BUF_CTL for HDMI")
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250214142001.552916-3-imre.deak@intel.com
(cherry picked from commit b2ecdabe46d23db275f94cd7c46ca414a144818b)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
index acb986bc1f33..2b9240ab547d 100644
--- a/drivers/gpu/drm/i915/display/intel_ddi.c
+++ b/drivers/gpu/drm/i915/display/intel_ddi.c
@@ -3487,7 +3487,7 @@ static void intel_ddi_enable_hdmi(struct intel_atomic_state *state,
 		intel_de_rmw(dev_priv, XELPDP_PORT_BUF_CTL1(dev_priv, port),
 			     XELPDP_PORT_WIDTH_MASK | XELPDP_PORT_REVERSAL, port_buf);
 
-		buf_ctl |= DDI_PORT_WIDTH(lane_count);
+		buf_ctl |= DDI_PORT_WIDTH(crtc_state->lane_count);
 
 		if (DISPLAY_VER(dev_priv) >= 20)
 			buf_ctl |= XE2LPD_DDI_BUF_D2D_LINK_ENABLE;
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 765e6c0528fb..786c727aea45 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -3633,7 +3633,7 @@ enum skl_power_gate {
 #define  DDI_BUF_IS_IDLE			(1 << 7)
 #define  DDI_BUF_CTL_TC_PHY_OWNERSHIP		REG_BIT(6)
 #define  DDI_A_4_LANES				(1 << 4)
-#define  DDI_PORT_WIDTH(width)			(((width) - 1) << 1)
+#define  DDI_PORT_WIDTH(width)			(((width) == 3 ? 4 : ((width) - 1)) << 1)
 #define  DDI_PORT_WIDTH_MASK			(7 << 1)
 #define  DDI_PORT_WIDTH_SHIFT			1
 #define  DDI_INIT_DISPLAY_DETECTED		(1 << 0)