The patch below does not apply to the 6.12-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-6.12.y git checkout FETCH_HEAD git cherry-pick -x c5c2b4b3841666be3a45346d0ffa96b4b143504e # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2025082335-unblock-ahead-61ea@gregkh' --subject-prefix 'PATCH 6.12.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

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

From c5c2b4b3841666be3a45346d0ffa96b4b143504e Mon Sep 17 00:00:00 2001 From: Imre Deak imre.deak@intel.com Date: Mon, 11 Aug 2025 11:01:51 +0300 Subject: [PATCH] drm/i915/lnl+/tc: Use the cached max lane count value

Use the cached max lane count value on LNL+, to account for scenarios where this value is queried after the HW cleared the corresponding pin assignment value in the TCSS_DDI_STATUS register after the sink got disconnected.

For consistency, follow-up changes will use the cached max lane count value on other platforms as well and will also cache the pin assignment value in a similar way.

Cc: stable@vger.kernel.org # v6.8+ Reported-by: Charlton Lin charlton.lin@intel.com Tested-by: Khaled Almahallawy khaled.almahallawy@intel.com Reviewed-by: Mika Kahola mika.kahola@intel.com Signed-off-by: Imre Deak imre.deak@intel.com Link: https://lore.kernel.org/r/20250811080152.906216-5-imre.deak@intel.com (cherry picked from commit afc4e84388079f4d5ba05271632b7a4d8d85165c) Signed-off-by: Tvrtko Ursulin tursulin@ursulin.net

diff --git a/drivers/gpu/drm/i915/display/intel_tc.c b/drivers/gpu/drm/i915/display/intel_tc.c index 3f9842040bb0..6a2442a0649e 100644 --- a/drivers/gpu/drm/i915/display/intel_tc.c +++ b/drivers/gpu/drm/i915/display/intel_tc.c @@ -395,12 +395,16 @@ static void read_pin_configuration(struct intel_tc_port *tc)

int intel_tc_port_max_lane_count(struct intel_digital_port *dig_port) { + struct intel_display *display = to_intel_display(dig_port); struct intel_tc_port *tc = to_tc_port(dig_port);

if (!intel_encoder_is_tc(&dig_port->base)) return 4;

- return get_max_lane_count(tc); + if (DISPLAY_VER(display) < 20) + return get_max_lane_count(tc); + + return tc->max_lane_count; }

void intel_tc_port_set_fia_lane_count(struct intel_digital_port *dig_port,