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.d... (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)