From 93ac092f054b25e41341b008fdb1ac69c9a8334c Mon Sep 17 00:00:00 2001 From: Manasi Navare Date: Tue, 30 Oct 2018 17:19:19 -0700 Subject: [PATCH] drm/i915/dp: Cache the DP/eDP DSC DPCD register set on Hotplug/eDP Init DSC is supported on eDP starting GEN 10 display (on GLK) and on DP starting GEN 11. This patch implements the discovery phase of DSC. On hotplug, source reads the DSC DPCD register set (0x00060 - 0x0006F) to read the decompression capabilities of the sink device. This entire block of registers is cached in intel_dp so that capability information can be used during DSC configuration phase during compute_config phase of the modeset. For eDP, this caching happens during the eDP initialization. This caching is done only for eDP and DP rev >= 1.4 v5: * Fix the block comment (Gaurav) * Fix the commit message DSC DPCD addresses (Gaurav) * Use DRM_ERROR for dpcd_read fail (Gaurav,Anusha) v4: * Cache these only for Gen >= 11 v3: * Remove the dsc_sink_support field in intel_dp (Jani N) v2: * Clear the cached registers on hotplug always (Jani N) * Combine the eDP and DP caching in same function (Jani N) Cc: Jani Nikula Cc: Ville Syrjala Cc: Daniel Vetter Cc: Anusha Srivatsa Cc: Gaurav K Singh Signed-off-by: Manasi Navare Reviewed-by: Anusha Srivatsa Reviewed-by: Gaurav K Singh Link: https://patchwork.freedesktop.org/patch/msgid/20181031001923.31442-3-manasi.d.navare@intel.com --- drivers/gpu/drm/i915/intel_dp.c | 32 ++++++++++++++++++++++++++++++++ drivers/gpu/drm/i915/intel_drv.h | 1 + 2 files changed, 33 insertions(+) diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index 6b37d66..eb3fada 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -3956,6 +3956,29 @@ intel_dp_read_dpcd(struct intel_dp *intel_dp) return intel_dp->dpcd[DP_DPCD_REV] != 0; } +static void intel_dp_get_dsc_sink_cap(struct intel_dp *intel_dp) +{ + /* + * Clear the cached register set to avoid using stale values + * for the sinks that do not support DSC. + */ + memset(intel_dp->dsc_dpcd, 0, sizeof(intel_dp->dsc_dpcd)); + + /* Cache the DSC DPCD if eDP or DP rev >= 1.4 */ + if (intel_dp->dpcd[DP_DPCD_REV] >= 0x14 || + intel_dp->edp_dpcd[0] >= DP_EDP_14) { + if (drm_dp_dpcd_read(&intel_dp->aux, DP_DSC_SUPPORT, + intel_dp->dsc_dpcd, + sizeof(intel_dp->dsc_dpcd)) < 0) + DRM_ERROR("Failed to read DPCD register 0x%x\n", + DP_DSC_SUPPORT); + + DRM_DEBUG_KMS("DSC DPCD: %*ph\n", + (int)sizeof(intel_dp->dsc_dpcd), + intel_dp->dsc_dpcd); + } +} + static bool intel_edp_init_dpcd(struct intel_dp *intel_dp) { @@ -4032,6 +4055,10 @@ intel_edp_init_dpcd(struct intel_dp *intel_dp) intel_dp_set_common_rates(intel_dp); + /* Read the eDP DSC DPCD registers */ + if (INTEL_GEN(dev_priv) >= 10 || IS_GEMINILAKE(dev_priv)) + intel_dp_get_dsc_sink_cap(intel_dp); + return true; } @@ -5126,6 +5153,7 @@ intel_dp_detect(struct drm_connector *connector, if (status == connector_status_disconnected) { memset(&intel_dp->compliance, 0, sizeof(intel_dp->compliance)); + memset(intel_dp->dsc_dpcd, 0, sizeof(intel_dp->dsc_dpcd)); if (intel_dp->is_mst) { DRM_DEBUG_KMS("MST device may have disappeared %d vs %d\n", @@ -5151,6 +5179,10 @@ intel_dp_detect(struct drm_connector *connector, intel_dp_print_rates(intel_dp); + /* Read DP Sink DSC Cap DPCD regs for DP v1.4 */ + if (INTEL_GEN(dev_priv) >= 11) + intel_dp_get_dsc_sink_cap(intel_dp); + drm_dp_read_desc(&intel_dp->aux, &intel_dp->desc, drm_dp_is_branch(intel_dp->dpcd)); diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h index e4eaa40..e827c16 100644 --- a/drivers/gpu/drm/i915/intel_drv.h +++ b/drivers/gpu/drm/i915/intel_drv.h @@ -1114,6 +1114,7 @@ struct intel_dp { uint8_t psr_dpcd[EDP_PSR_RECEIVER_CAP_SIZE]; uint8_t downstream_ports[DP_MAX_DOWNSTREAM_PORTS]; uint8_t edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE]; + u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE]; /* source rates */ int num_source_rates; const int *source_rates; -- 2.7.4