From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 6371EC678D4 for ; Tue, 7 Mar 2023 09:10:05 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 51A9010E387; Tue, 7 Mar 2023 09:10:04 +0000 (UTC) Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by gabe.freedesktop.org (Postfix) with ESMTPS id 5628010E387; Tue, 7 Mar 2023 09:10:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1678180201; x=1709716201; h=from:to:cc:subject:in-reply-to:references:date: message-id:mime-version; bh=EF3mCJC1nMFMnnDqKO4lCNZrKiMjBiQPNck/EAiz2fc=; b=lpA5cId7QW8Yl5DgInehPgzRI3GzvX6a+XT5aZ3jo81D3g2Wkk+rhE9x iAcaVpvK8mg0AO9UlO2azUS9fi+NL4zuTnq9bIUsQPe1EQxOv7QMU+BTg kTOWOo8GgwRui24I/MSonlQF7K6N5UBu8J1IfBmwF8oQcQqTAC8+tOWEr nwCtN+BRgeWCizapg+9WRcD24ln/fgYkqQMcLuN9miV2ss8Gy/96LJiCE iJOd21Y1PRLp4RVaDHiHKy3pgGKZFe7afnSBzgMxXSBGFksDSFxryWou1 g6gLFZLgwy0/X/JHOTxkir/TTztLJtNu7Az4uhYCwm3UtSn0633ZKiKTh Q==; X-IronPort-AV: E=McAfee;i="6500,9779,10641"; a="333274781" X-IronPort-AV: E=Sophos;i="5.98,240,1673942400"; d="scan'208";a="333274781" Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Mar 2023 01:10:00 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10641"; a="850630860" X-IronPort-AV: E=Sophos;i="5.98,240,1673942400"; d="scan'208";a="850630860" Received: from sbarnes-mobl1.ger.corp.intel.com (HELO localhost) ([10.252.58.236]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Mar 2023 01:09:59 -0800 From: Jani Nikula To: Arun R Murthy , intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org In-Reply-To: <20230302081532.765821-3-arun.r.murthy@intel.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo References: <20230302081532.765821-1-arun.r.murthy@intel.com> <20230302081532.765821-3-arun.r.murthy@intel.com> Date: Tue, 07 Mar 2023 11:09:56 +0200 Message-ID: <87o7p5rkpn.fsf@intel.com> MIME-Version: 1.0 Content-Type: text/plain Subject: Re: [Intel-gfx] [PATCHv4 2/2] i915/display/dp: SDP CRC16 for 128b132b link layer X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On Thu, 02 Mar 2023, Arun R Murthy wrote: > Enable SDP error detection configuration, this will set CRC16 in > 128b/132b link layer. > For Display version 13 a hardware bit31 in register VIDEO_DIP_CTL is > added to enable/disable SDP CRC applicable for DP2.0 only, but the > default value of this bit will enable CRC16 in 128b/132b hence > skipping this write. > Corrective actions on SDP corruption is yet to be defined. > > v2: Moved the CRC enable to link training init(Jani N) > v3: Moved crc enable to ddi pre enable > v4: Separate function for SDP CRC16 (Jani N) > > Signed-off-by: Arun R Murthy Reviewed-by: Jani Nikula > --- > drivers/gpu/drm/i915/display/intel_ddi.c | 4 ++++ > .../drm/i915/display/intel_dp_link_training.c | 20 +++++++++++++++++++ > .../drm/i915/display/intel_dp_link_training.h | 2 ++ > 3 files changed, 26 insertions(+) > > diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c > index e5979427b38b..127b3035f92d 100644 > --- a/drivers/gpu/drm/i915/display/intel_ddi.c > +++ b/drivers/gpu/drm/i915/display/intel_ddi.c > @@ -2519,6 +2519,10 @@ static void intel_ddi_pre_enable_dp(struct intel_atomic_state *state, > { > struct drm_i915_private *dev_priv = to_i915(encoder->base.dev); > > + if (HAS_DP20(dev_priv)) > + intel_dp_128b132b_sdp_crc16(enc_to_intel_dp(encoder), > + crtc_state); > + > if (DISPLAY_VER(dev_priv) >= 12) > tgl_ddi_pre_enable_dp(state, encoder, crtc_state, conn_state); > else > diff --git a/drivers/gpu/drm/i915/display/intel_dp_link_training.c b/drivers/gpu/drm/i915/display/intel_dp_link_training.c > index 3d3efcf02011..35d31e4efab9 100644 > --- a/drivers/gpu/drm/i915/display/intel_dp_link_training.c > +++ b/drivers/gpu/drm/i915/display/intel_dp_link_training.c > @@ -1454,3 +1454,23 @@ void intel_dp_start_link_train(struct intel_dp *intel_dp, > if (!passed) > intel_dp_schedule_fallback_link_training(intel_dp, crtc_state); > } > + > +void intel_dp_128b132b_sdp_crc16(struct intel_dp *intel_dp, > + const struct intel_crtc_state *crtc_state) > +{ > + struct drm_i915_private *i915 = dp_to_i915(intel_dp); > + > + /* > + * VIDEO_DIP_CTL register bit 31 should be set to '0' to not > + * disable SDP CRC. This is applicable for Display version 13. > + * Default value of bit 31 is '0' hence discarding the write > + * TODO: Corrective actions on SDP corruption yet to be defined > + */ > + if (intel_dp_is_uhbr(crtc_state)) > + /* DP v2.0 SCR on SDP CRC16 for 128b/132b Link Layer */ > + drm_dp_dpcd_writeb(&intel_dp->aux, > + DP_SDP_ERROR_DETECTION_CONFIGURATION, > + DP_SDP_CRC16_128B132B_EN); > + > + drm_dbg_kms(&i915->drm, "DP2.0 SDP CRC16 for 128b/132b enabled\n"); > +} > diff --git a/drivers/gpu/drm/i915/display/intel_dp_link_training.h b/drivers/gpu/drm/i915/display/intel_dp_link_training.h > index 7fa1c0833096..2c8f2775891b 100644 > --- a/drivers/gpu/drm/i915/display/intel_dp_link_training.h > +++ b/drivers/gpu/drm/i915/display/intel_dp_link_training.h > @@ -39,4 +39,6 @@ static inline u8 intel_dp_training_pattern_symbol(u8 pattern) > return pattern & ~DP_LINK_SCRAMBLING_DISABLE; > } > > +void intel_dp_128b132b_sdp_crc16(struct intel_dp *intel_dp, > + const struct intel_crtc_state *crtc_state); > #endif /* __INTEL_DP_LINK_TRAINING_H__ */ -- Jani Nikula, Intel Open Source Graphics Center