Patch "Revert "drm/dp: Change AUX DPCD probe address from DPCD_REV to LANE0_1_STATUS"" has been added to the 6.12-stable tree

Patch "Revert "drm/dp: Change AUX DPCD probe address from DPCD_REV to LANE0_1_STATUS"" has been added to the 6.12-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    Revert "drm/dp: Change AUX DPCD probe address from DPCD_REV to LANE0_1_STATUS"

to the 6.12-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:
     revert-drm-dp-change-aux-dpcd-probe-address-from-dpcd_rev-to-lane0_1_status.patch
and it can be found in the queue-6.12 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


From imre.deak@intel.com  Tue Sep  2 13:50:59 2025
From: Imre Deak <imre.deak@intel.com>
Date: Thu, 28 Aug 2025 20:49:29 +0300
Subject: Revert "drm/dp: Change AUX DPCD probe address from DPCD_REV to LANE0_1_STATUS"
To: <stable@vger.kernel.org>
Cc: <intel-gfx@lists.freedesktop.org>, <dri-devel@lists.freedesktop.org>, Sasha Levin <sashal@kernel.org>

From: Imre Deak <imre.deak@intel.com>

This reverts commit 3c778a98bee16b4c7ba364a0101ee3c399a95b85 which is
commit a40c5d727b8111b5db424a1e43e14a1dcce1e77f upstream.

The upstream commit a40c5d727b8111b5db424a1e43e14a1dcce1e77f ("drm/dp:
Change AUX DPCD probe address from DPCD_REV to LANE0_1_STATUS") the
reverted commit backported causes a regression, on one eDP panel at
least resulting in display flickering, described in detail at the Link:
below. The issue fixed by the upstream commit will need a different
solution, revert the backport for now.

Cc: intel-gfx@lists.freedesktop.org
Cc: dri-devel@lists.freedesktop.org
Cc: Sasha Levin <sashal@kernel.org>
Link: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/14558
Signed-off-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/gpu/drm/display/drm_dp_helper.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/gpu/drm/display/drm_dp_helper.c
+++ b/drivers/gpu/drm/display/drm_dp_helper.c
@@ -664,7 +664,7 @@ ssize_t drm_dp_dpcd_read(struct drm_dp_a
 	 * monitor doesn't power down exactly after the throw away read.
 	 */
 	if (!aux->is_remote) {
-		ret = drm_dp_dpcd_probe(aux, DP_LANE0_1_STATUS);
+		ret = drm_dp_dpcd_probe(aux, DP_DPCD_REV);
 		if (ret < 0)
 			return ret;
 	}


Patches currently in stable-queue which might be from imre.deak@intel.com are

queue-6.12/revert-drm-dp-change-aux-dpcd-probe-address-from-dpcd_rev-to-lane0_1_status.patch