Patch "drm/amdgpu: fix DP mode validation" has been added to the 4.5-stable tree

Patch "drm/amdgpu: fix DP mode validation" has been added to the 4.5-stable tree

[gregkh]

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

    drm/amdgpu: fix DP mode validation

to the 4.5-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-amdgpu-fix-dp-mode-validation.patch
and it can be found in the queue-4.5 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 c47b9e0944e483309d66c807d650ac8b8ceafb57 Mon Sep 17 00:00:00 2001
From: Alex Deucher <alexander.deucher@amd.com>
Date: Wed, 11 May 2016 16:21:03 -0400
Subject: drm/amdgpu: fix DP mode validation

From: Alex Deucher <alexander.deucher@amd.com>

commit c47b9e0944e483309d66c807d650ac8b8ceafb57 upstream.

Switch the order of the loops to walk the rates on the top
so we exhaust all DP 1.1 rate/lane combinations before trying
DP 1.2 rate/lane combos.

This avoids selecting rates that are supported by the monitor,
but not the connector leading to valid modes getting rejected.

bug:
https://bugs.freedesktop.org/show_bug.cgi?id=95206

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/gpu/drm/amd/amdgpu/atombios_dp.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/gpu/drm/amd/amdgpu/atombios_dp.c
+++ b/drivers/gpu/drm/amd/amdgpu/atombios_dp.c
@@ -276,8 +276,8 @@ static int amdgpu_atombios_dp_get_dp_lin
 			}
 		}
 	} else {
-		for (lane_num = 1; lane_num <= max_lane_num; lane_num <<= 1) {
-			for (i = 0; i < ARRAY_SIZE(link_rates) && link_rates[i] <= max_link_rate; i++) {
+		for (i = 0; i < ARRAY_SIZE(link_rates) && link_rates[i] <= max_link_rate; i++) {
+			for (lane_num = 1; lane_num <= max_lane_num; lane_num <<= 1) {
 				max_pix_clock = (lane_num * link_rates[i] * 8) / bpp;
 				if (max_pix_clock >= pix_clock) {
 					*dp_lanes = lane_num;


Patches currently in stable-queue which might be from alexander.deucher@amd.com are

queue-4.5/drm-radeon-fix-pll-sharing-on-dce6.1-v2.patch
queue-4.5/drm-amdgpu-fix-dp-mode-validation.patch
queue-4.5/drm-radeon-fix-dp-mode-validation.patch
queue-4.5/drm-radeon-fix-dp-link-training-issue-with-second-4k-monitor.patch