From patchwork Thu Nov 29 18:34:05 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Navare, Manasi" X-Patchwork-Id: 10705199 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id BE99113BF for ; Thu, 29 Nov 2018 18:31:17 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B18892F675 for ; Thu, 29 Nov 2018 18:31:17 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A59E32F6C3; Thu, 29 Nov 2018 18:31:17 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 38DE62F675 for ; Thu, 29 Nov 2018 18:31:17 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id AA3F36E4C5; Thu, 29 Nov 2018 18:31:16 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by gabe.freedesktop.org (Postfix) with ESMTPS id C8D476E4C5 for ; Thu, 29 Nov 2018 18:31:14 +0000 (UTC) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga107.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 29 Nov 2018 10:31:14 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.56,295,1539673200"; d="scan'208";a="96864373" Received: from labuser-z97x-ud5h.jf.intel.com ([10.54.75.151]) by orsmga008.jf.intel.com with ESMTP; 29 Nov 2018 10:31:13 -0800 From: Manasi Navare To: intel-gfx@lists.freedesktop.org Date: Thu, 29 Nov 2018 10:34:05 -0800 Message-Id: <20181129183405.32356-1-manasi.d.navare@intel.com> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181127205132.1001-1-manasi.d.navare@intel.com> References: <20181127205132.1001-1-manasi.d.navare@intel.com> MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH v8] drm/i915: implement EXTENDED_RECEIVER_CAPABILITY_FIELD_PRESENT X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.23 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" X-Virus-Scanned: ClamAV using ClamSMTP From: Matt Atwood According to DP spec (2.9.3.1 of DP 1.4) if EXTENDED_RECEIVER_CAPABILITY_FIELD_PRESENT is set the addresses in DPCD 02200h through 0220Fh shall contain the DPRX's true capability. These values will match 00000h through 0000Fh, except for DPCD_REV, MAX_LINK_RATE, DOWN_STREAM_PORT_PRESENT. Read from DPCD once for all 3 values as this is an expensive operation. Spec mentions that all of address space 02200h through 0220Fh should contain the right information however currently only 3 values can differ. There is no address space in the intel_dp->dpcd struct for addresses 02200h through 0220Fh, and since so much of the data is a identical, simply overwrite the values stored in 00000h through 0000Fh with the values that can be overwritten from addresses 02200h through 0220Fh. This patch helps with backward compatibility for devices pre DP1.3. v2: read only dpcd values which can be affected, remove incorrect check, split into drm include changes into separate patch, commit message, verbose debugging statements during overwrite. v3: white space fixes v4: make path dependent on DPCD revision > 1.2 v5: split into function, removed DPCD rev check v6: add debugging prints for early exit conditions v7 (From Manasi): * Memcpy, memcmp and debig logging based on sizeof(dpcd_ext) (Jani N) * Exit early (Jani N) v8 (From Manasi): * Get rid of superfluous debug prints (Jani N) * Print entire base DPCD before memcpy (Jani N) Cc: Jani Nikula Cc: Ville Syrjala Signed-off-by: Matt Atwood Tested-by: Manasi Navare Acked-by: Manasi Navare Reviewed-by: Rodrigo Vivi Reviewed-by: Rodrigo Vivi --- drivers/gpu/drm/i915/intel_dp.c | 35 +++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index 70ae3d57316b..5698441abe47 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -3802,6 +3802,39 @@ intel_dp_link_down(struct intel_encoder *encoder, } } +static void +intel_dp_extended_receiver_capabilities(struct intel_dp *intel_dp) +{ + u8 dpcd_ext[6]; + + /* + * Prior to DP1.3 the bit represented by + * DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT was reserved. + * if it is set DP_DPCD_REV at 0000h could be at a value less than + * the true capability of the panel. The only way to check is to + * then compare 0000h and 2200h. + */ + if (!(intel_dp->dpcd[DP_TRAINING_AUX_RD_INTERVAL] & + DP_EXTENDED_RECEIVER_CAP_FIELD_PRESENT)) + return; + + if (drm_dp_dpcd_read(&intel_dp->aux, DP_DP13_DPCD_REV, + &dpcd_ext, sizeof(dpcd_ext)) != sizeof(dpcd_ext)) { + DRM_ERROR("DPCD failed read at extended capabilities\n"); + return; + } + if (intel_dp->dpcd[DP_DPCD_REV] > dpcd_ext[DP_DPCD_REV]) { + DRM_DEBUG_KMS("DPCD extended DPCD rev less than base DPCD rev\n"); + return; + } + if (!memcmp(intel_dp->dpcd, dpcd_ext, sizeof(dpcd_ext))) + return; + + DRM_DEBUG_KMS("Base DPCD: %*ph\n", + (int)sizeof(intel_dp->dpcd), intel_dp->dpcd); + memcpy(intel_dp->dpcd, dpcd_ext, sizeof(dpcd_ext)); +} + bool intel_dp_read_dpcd(struct intel_dp *intel_dp) { @@ -3809,6 +3842,8 @@ intel_dp_read_dpcd(struct intel_dp *intel_dp) sizeof(intel_dp->dpcd)) < 0) return false; /* aux transfer failed */ + intel_dp_extended_receiver_capabilities(intel_dp); + DRM_DEBUG_KMS("DPCD: %*ph\n", (int) sizeof(intel_dp->dpcd), intel_dp->dpcd); return intel_dp->dpcd[DP_DPCD_REV] != 0;