This is a note to let you know that I've just added the patch titled drm/i915/cnp: Ignore VBT request for know invalid DDC pin. to the 4.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: drm-i915-cnp-ignore-vbt-request-for-know-invalid-ddc-pin.patch and it can be found in the queue-4.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From f24c606c21a8cb6f75adc20edcd80b6d851991bf Mon Sep 17 00:00:00 2001 From: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx> Date: Tue, 23 Jan 2018 09:40:50 -0800 Subject: drm/i915/cnp: Ignore VBT request for know invalid DDC pin. From: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx> commit f24c606c21a8cb6f75adc20edcd80b6d851991bf upstream. Let's ignore VBT request if the pin is clearly wrong. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=104139 Cc: Kai Heng Feng <kai.heng.feng@xxxxxxxxxxxxx> Signed-off-by: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx> Link: https://patchwork.freedesktop.org/patch/msgid/20180123174050.4261-1-rodrigo.vivi@xxxxxxxxx Reviewed-by: Radhakrishna Sripada <radhakrishna.sripada@xxxxxxxxx> (cherry picked from commit a8e6f3888b05c1e7b685800a3371ce050720368f) Signed-off-by: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/i915/intel_bios.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) --- a/drivers/gpu/drm/i915/intel_bios.c +++ b/drivers/gpu/drm/i915/intel_bios.c @@ -1115,9 +1115,14 @@ static const u8 cnp_ddc_pin_map[] = { static u8 map_ddc_pin(struct drm_i915_private *dev_priv, u8 vbt_pin) { - if (HAS_PCH_CNP(dev_priv) && - vbt_pin > 0 && vbt_pin < ARRAY_SIZE(cnp_ddc_pin_map)) - return cnp_ddc_pin_map[vbt_pin]; + if (HAS_PCH_CNP(dev_priv)) { + if (vbt_pin > 0 && vbt_pin < ARRAY_SIZE(cnp_ddc_pin_map)) + return cnp_ddc_pin_map[vbt_pin]; + if (vbt_pin > GMBUS_PIN_4_CNP) { + DRM_DEBUG_KMS("Ignoring alternate pin: VBT claims DDC pin %d, which is not valid for this platform\n", vbt_pin); + return 0; + } + } return vbt_pin; } Patches currently in stable-queue which might be from rodrigo.vivi@xxxxxxxxx are queue-4.15/drm-i915-cnp-properly-handle-vbt-ddc-pin-out-of-bounds.patch queue-4.15/drm-i915-cnp-ignore-vbt-request-for-know-invalid-ddc-pin.patch