From 98a818632beb6ae5e1151649a7b0b7514857c689 Mon Sep 17 00:00:00 2001 From: Rodrigo Vivi Date: Mon, 29 Sep 2014 18:29:52 -0400 Subject: [PATCH] drm/i915: preserve other DP_TEST_SINK bits. Sink crc was implemented based on dp 1.1 spec that had all TEST_SINK bits reserved reading all 0s. But when reviewing my latest changes on sink crc Todd warned me that on new specs we have other valid bits on this reg that we might want to preserve. Cc: Todd Previte Signed-off-by: Rodrigo Vivi Reviewed-by: Todd Previte Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/intel_dp.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index 3caac0f01265c..342d624f83125 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -3817,8 +3817,9 @@ int intel_dp_sink_crc(struct intel_dp *intel_dp, u8 *crc) if (!(buf & DP_TEST_CRC_SUPPORTED)) return -ENOTTY; + drm_dp_dpcd_readb(&intel_dp->aux, DP_TEST_SINK, &buf); if (drm_dp_dpcd_writeb(&intel_dp->aux, DP_TEST_SINK, - DP_TEST_SINK_START) < 0) + buf | DP_TEST_SINK_START) < 0) return -EIO; drm_dp_dpcd_readb(&intel_dp->aux, DP_TEST_SINK_MISC, &buf); @@ -3837,7 +3838,10 @@ int intel_dp_sink_crc(struct intel_dp *intel_dp, u8 *crc) if (drm_dp_dpcd_read(&intel_dp->aux, DP_TEST_CRC_R_CR, crc, 6) < 0) return -EIO; - drm_dp_dpcd_writeb(&intel_dp->aux, DP_TEST_SINK, 0); + drm_dp_dpcd_readb(&intel_dp->aux, DP_TEST_SINK, &buf); + drm_dp_dpcd_writeb(&intel_dp->aux, DP_TEST_SINK, + buf & ~DP_TEST_SINK_START); + return 0; } -- 2.39.5