drm/radeon: fix DP mode validation
authorAlex Deucher <alexander.deucher@amd.com>
Wed, 11 May 2016 20:16:53 +0000 (16:16 -0400)
committerAlex Deucher <alexander.deucher@amd.com>
Thu, 12 May 2016 19:03:39 +0000 (15:03 -0400)
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>
Cc: stable@vger.kernel.org
drivers/gpu/drm/radeon/atombios_dp.c

index afa9db1dc0e3dfcc14f51bf3e74b2f2d3c5702c5..cead089a9e7d2ea1bc78046aeed4d6cb7e8a02d6 100644 (file)
@@ -326,8 +326,8 @@ int radeon_dp_get_dp_link_config(struct drm_connector *connector,
                        }
                }
        } 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;