From 6bdf63fe8999171e65f6b65bf837d3c5f8571da1 Mon Sep 17 00:00:00 2001 From: Alex Deucher Date: Wed, 11 May 2016 16:16:53 -0400 Subject: [PATCH] drm/radeon: fix DP mode validation [ Upstream commit ff0bd441bdfbfa09d05fdba9829a0401a46635c1 ] 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 Cc: stable@vger.kernel.org Signed-off-by: Sasha Levin --- drivers/gpu/drm/radeon/atombios_dp.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/radeon/atombios_dp.c b/drivers/gpu/drm/radeon/atombios_dp.c index 7ac42d0..c868acb 100644 --- a/drivers/gpu/drm/radeon/atombios_dp.c +++ b/drivers/gpu/drm/radeon/atombios_dp.c @@ -325,8 +325,8 @@ 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; -- 2.7.4