The patch below does not apply to the 4.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable@xxxxxxxxxxxxxxx>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From c8213a638f65bf487c10593c216525952cca3690 Mon Sep 17 00:00:00 2001 From: Alex Deucher <alexander.deucher@xxxxxxx> Date: Thu, 3 Mar 2016 19:26:24 -0500 Subject: [PATCH] drm/radeon/dp: add back special handling for NUTMEG MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When I fixed the dp rate selection in: 092c96a8ab9d1bd60ada2ed385cc364ce084180e drm/radeon: fix dp link rate selection (v2) I accidently dropped the special handling for NUTMEG DP bridge chips. They require a fixed link rate. Reviewed-by: Christian König <christian.koenig@xxxxxxx> Reviewed-by: Ken Wang <Qingqing.Wang@xxxxxxx> Reviewed-by: Harry Wentland <harry.wentland@xxxxxxx> Tested-by: Ken Moffat <zarniwhoop@xxxxxxxxxxxx> Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx> Cc: stable@xxxxxxxxxxxxxxx diff --git a/drivers/gpu/drm/radeon/atombios_dp.c b/drivers/gpu/drm/radeon/atombios_dp.c index 44ee72e04df9..6af832545bc5 100644 --- a/drivers/gpu/drm/radeon/atombios_dp.c +++ b/drivers/gpu/drm/radeon/atombios_dp.c @@ -315,15 +315,27 @@ int radeon_dp_get_dp_link_config(struct drm_connector *connector, unsigned max_lane_num = drm_dp_max_lane_count(dpcd); unsigned lane_num, i, max_pix_clock; - 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++) { - max_pix_clock = (lane_num * link_rates[i] * 8) / bpp; + if (radeon_connector_encoder_get_dp_bridge_encoder_id(connector) == + ENCODER_OBJECT_ID_NUTMEG) { + for (lane_num = 1; lane_num <= max_lane_num; lane_num <<= 1) { + max_pix_clock = (lane_num * 270000 * 8) / bpp; if (max_pix_clock >= pix_clock) { *dp_lanes = lane_num; - *dp_rate = link_rates[i]; + *dp_rate = 270000; return 0; } } + } 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++) { + max_pix_clock = (lane_num * link_rates[i] * 8) / bpp; + if (max_pix_clock >= pix_clock) { + *dp_lanes = lane_num; + *dp_rate = link_rates[i]; + return 0; + } + } + } } return -EINVAL; -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html