From: Rodrigo Vivi Date: Mon, 29 Sep 2014 22:29:52 +0000 (-0400) Subject: drm/i915: preserve other DP_TEST_SINK bits. X-Git-Tag: v6.6-pxa1908~22050^2~79^2~22 X-Git-Url: https://git.dujemihanovic.xyz/?a=commitdiff_plain;h=ce31d9f4fc05964f6c0dd3a8661dc1a1d843a1e2;p=linux.git 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 --- diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index 3caac0f01265..342d624f8312 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; }