From 140ef138db07285b9eecf14ae3ee7c0a407ab93a Mon Sep 17 00:00:00 2001 From: Manasi Navare Date: Thu, 8 Jun 2017 13:41:03 -0700 Subject: [PATCH] drm/i915/dp: Validate the compliance test link parameters Validate the compliance test link parameters when the compliance test dpcd registers are read. Also validate them in compute_config before using them since the max values might have been reduced due to link training fallback. If either the link rate or lane count is invalid, we still bail from using the test parameters since the combination would not work and instead use the fallback values. v2: * Added commit message to explain why we still bail when either of of the params is invalid (Ville Syrjala) * Add reason for validating in the comment (Jani Nikula) * Also check if index >= 0 after validating (Jani Nikula) Signed-off-by: Manasi Navare Cc: Jani Nikula Cc: Ville Syrjala Reviewed-by: Jani Nikula Tested-by: Nathan Ciobanu Signed-off-by: Jani Nikula Link: https://patchwork.freedesktop.org/patch/msgid/1496954463-18038-2-git-send-email-manasi.d.navare@intel.com --- drivers/gpu/drm/i915/intel_dp.c | 34 ++++++++++++++++----------------- 1 file changed, 17 insertions(+), 17 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index de2aaad19714..e5f787319725 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -1690,12 +1690,18 @@ intel_dp_compute_config(struct intel_encoder *encoder, if (intel_dp->compliance.test_type == DP_TEST_LINK_TRAINING) { int index; - index = intel_dp_rate_index(intel_dp->common_rates, - intel_dp->num_common_rates, - intel_dp->compliance.test_link_rate); - if (index >= 0) - min_clock = max_clock = index; - min_lane_count = max_lane_count = intel_dp->compliance.test_lane_count; + /* Validate the compliance test data since max values + * might have changed due to link train fallback. + */ + if (intel_dp_link_params_valid(intel_dp, intel_dp->compliance.test_link_rate, + intel_dp->compliance.test_lane_count)) { + index = intel_dp_rate_index(intel_dp->common_rates, + intel_dp->num_common_rates, + intel_dp->compliance.test_link_rate); + if (index >= 0) + min_clock = max_clock = index; + min_lane_count = max_lane_count = intel_dp->compliance.test_lane_count; + } } DRM_DEBUG_KMS("DP link computation with max lane count %i " "max bw %d pixel clock %iKHz\n", @@ -3976,8 +3982,7 @@ intel_dp_get_sink_irq_esi(struct intel_dp *intel_dp, u8 *sink_irq_vector) static uint8_t intel_dp_autotest_link_training(struct intel_dp *intel_dp) { int status = 0; - int min_lane_count = 1; - int link_rate_index, test_link_rate; + int test_link_rate; uint8_t test_lane_count, test_link_bw; /* (DP CTS 1.2) * 4.3.1.11 @@ -3991,10 +3996,6 @@ static uint8_t intel_dp_autotest_link_training(struct intel_dp *intel_dp) return DP_TEST_NAK; } test_lane_count &= DP_MAX_LANE_COUNT_MASK; - /* Validate the requested lane count */ - if (test_lane_count < min_lane_count || - test_lane_count > intel_dp->max_link_lane_count) - return DP_TEST_NAK; status = drm_dp_dpcd_readb(&intel_dp->aux, DP_TEST_LINK_RATE, &test_link_bw); @@ -4002,12 +4003,11 @@ static uint8_t intel_dp_autotest_link_training(struct intel_dp *intel_dp) DRM_DEBUG_KMS("Link Rate read failed\n"); return DP_TEST_NAK; } - /* Validate the requested link rate */ test_link_rate = drm_dp_bw_code_to_link_rate(test_link_bw); - link_rate_index = intel_dp_rate_index(intel_dp->common_rates, - intel_dp->num_common_rates, - test_link_rate); - if (link_rate_index < 0) + + /* Validate the requested link rate and lane count */ + if (!intel_dp_link_params_valid(intel_dp, test_link_rate, + test_lane_count)) return DP_TEST_NAK; intel_dp->compliance.test_lane_count = test_lane_count; -- 2.20.1