From patchwork Wed Sep 12 06:22:50 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lee Shawn C X-Patchwork-Id: 10596731 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 E4E7214DB for ; Wed, 12 Sep 2018 05:51:50 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D33412979D for ; Wed, 12 Sep 2018 05:51:50 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id C77CC299BC; Wed, 12 Sep 2018 05:51:50 +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 4A7032979D for ; Wed, 12 Sep 2018 05:51:50 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 75B146E448; Wed, 12 Sep 2018 05:51:43 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by gabe.freedesktop.org (Postfix) with ESMTPS id 4DD3D6E43C; Wed, 12 Sep 2018 05:51:42 +0000 (UTC) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by fmsmga101.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 11 Sep 2018 22:51:41 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.53,363,1531810800"; d="scan'208";a="69330455" Received: from shawnle1-cm6330.itwn.intel.com ([10.5.230.140]) by fmsmga007.fm.intel.com with ESMTP; 11 Sep 2018 22:51:37 -0700 From: "Lee, Shawn C" To: intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org Subject: [PATCH v4 2/3] drm: Change limited M/N quirk to constant N quirk. Date: Tue, 11 Sep 2018 23:22:50 -0700 Message-Id: <1536733371-25004-3-git-send-email-shawn.c.lee@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1536733371-25004-1-git-send-email-shawn.c.lee@intel.com> References: <1536733371-25004-1-git-send-email-shawn.c.lee@intel.com> X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Cooper Chiou , Lee@freedesktop.org, Jani Nikula , Matt Atwood , Dhinakaran Pandiyan , "Lee, Shawn C" MIME-Version: 1.0 Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Virus-Scanned: ClamAV using ClamSMTP Some DP dongles in particular seem to be fussy about too large link M/N values. Set specific value for N divider can resolve this issue per dongle vendor's comment. So configure N as constant value (0x8000) to instead of reduce M/N formula when specific DP dongle connected. v2: add more comments for issue description and fix typo. v3: add lost commit messages back for version 2 v4: send patch to both intel-gfx and dri-devel Cc: Jani Nikula Cc: Cooper Chiou Cc: Matt Atwood Cc: Maarten Lankhorst Cc: Dhinakaran Pandiyan Cc: Clint Taylor Signed-off-by: Lee, Shawn C --- drivers/gpu/drm/drm_dp_helper.c | 2 +- drivers/gpu/drm/i915/intel_display.c | 28 +++++++++++++--------------- drivers/gpu/drm/i915/intel_display.h | 2 +- drivers/gpu/drm/i915/intel_dp.c | 8 ++++---- drivers/gpu/drm/i915/intel_dp_mst.c | 6 +++--- include/drm/drm_dp_helper.h | 6 +++--- 6 files changed, 25 insertions(+), 27 deletions(-) diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index 0362c645d96e..f3a7563eb8a1 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -1269,7 +1269,7 @@ struct dpcd_quirk { static const struct dpcd_quirk dpcd_quirk_list[] = { /* Analogix 7737 needs reduced M and N at HBR2 link rates */ - { OUI(0x00, 0x22, 0xb9), DEVICE_ID_ANY, true, BIT(DP_DPCD_QUIRK_LIMITED_M_N) }, + { OUI(0x00, 0x22, 0xb9), DEVICE_ID_ANY, true, BIT(DP_DPCD_QUIRK_CONSTANT_N) }, }; #undef OUI diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index ec3e24f07486..da0c7fbef3ef 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -6680,22 +6680,20 @@ intel_reduce_m_n_ratio(uint32_t *num, uint32_t *den) static void compute_m_n(unsigned int m, unsigned int n, uint32_t *ret_m, uint32_t *ret_n, - bool reduce_m_n) + bool constant_n) { /* - * Reduce M/N as much as possible without loss in precision. Several DP - * dongles in particular seem to be fussy about too large *link* M/N - * values. The passed in values are more likely to have the least - * significant bits zero than M after rounding below, so do this first. + * Several DP dongles in particular seem to be fussy about + * too large link M/N values. Give N value as 0x8000 that + * should be acceptable by specific devices. 0x8000 is the + * specified fixed N value for asynchronous clock mode, + * which the devices expect also in synchronous clock mode. */ - if (reduce_m_n) { - while ((m & 1) == 0 && (n & 1) == 0) { - m >>= 1; - n >>= 1; - } - } + if (constant_n) + *ret_n = 0x8000; + else + *ret_n = min_t(unsigned int, roundup_pow_of_two(n), DATA_LINK_N_MAX); - *ret_n = min_t(unsigned int, roundup_pow_of_two(n), DATA_LINK_N_MAX); *ret_m = div_u64((uint64_t) m * *ret_n, n); intel_reduce_m_n_ratio(ret_m, ret_n); } @@ -6704,18 +6702,18 @@ void intel_link_compute_m_n(int bits_per_pixel, int nlanes, int pixel_clock, int link_clock, struct intel_link_m_n *m_n, - bool reduce_m_n) + bool constant_n) { m_n->tu = 64; compute_m_n(bits_per_pixel * pixel_clock, link_clock * nlanes * 8, &m_n->gmch_m, &m_n->gmch_n, - reduce_m_n); + constant_n); compute_m_n(pixel_clock, link_clock, &m_n->link_m, &m_n->link_n, - reduce_m_n); + constant_n); } static inline bool intel_panel_use_ssc(struct drm_i915_private *dev_priv) diff --git a/drivers/gpu/drm/i915/intel_display.h b/drivers/gpu/drm/i915/intel_display.h index 43f080c6538d..8e8bd5eed2c2 100644 --- a/drivers/gpu/drm/i915/intel_display.h +++ b/drivers/gpu/drm/i915/intel_display.h @@ -379,7 +379,7 @@ struct intel_link_m_n { void intel_link_compute_m_n(int bpp, int nlanes, int pixel_clock, int link_clock, struct intel_link_m_n *m_n, - bool reduce_m_n); + bool constant_n); bool is_ccs_modifier(u64 modifier); #endif diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index 436c22de33b6..6b4c19123f2a 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -1998,8 +1998,8 @@ intel_dp_compute_config(struct intel_encoder *encoder, struct intel_connector *intel_connector = intel_dp->attached_connector; struct intel_digital_connector_state *intel_conn_state = to_intel_digital_connector_state(conn_state); - bool reduce_m_n = drm_dp_has_quirk(&intel_dp->desc, - DP_DPCD_QUIRK_LIMITED_M_N); + bool constant_n = drm_dp_has_quirk(&intel_dp->desc, + DP_DPCD_QUIRK_CONSTANT_N); if (HAS_PCH_SPLIT(dev_priv) && !HAS_DDI(dev_priv) && port != PORT_A) pipe_config->has_pch_encoder = true; @@ -2064,7 +2064,7 @@ intel_dp_compute_config(struct intel_encoder *encoder, adjusted_mode->crtc_clock, pipe_config->port_clock, &pipe_config->dp_m_n, - reduce_m_n); + constant_n); if (intel_connector->panel.downclock_mode != NULL && dev_priv->drrs.type == SEAMLESS_DRRS_SUPPORT) { @@ -2074,7 +2074,7 @@ intel_dp_compute_config(struct intel_encoder *encoder, intel_connector->panel.downclock_mode->clock, pipe_config->port_clock, &pipe_config->dp_m2_n2, - reduce_m_n); + constant_n); } if (!HAS_DDI(dev_priv)) diff --git a/drivers/gpu/drm/i915/intel_dp_mst.c b/drivers/gpu/drm/i915/intel_dp_mst.c index 352e5216cc65..184023435b08 100644 --- a/drivers/gpu/drm/i915/intel_dp_mst.c +++ b/drivers/gpu/drm/i915/intel_dp_mst.c @@ -45,8 +45,8 @@ static bool intel_dp_mst_compute_config(struct intel_encoder *encoder, int lane_count, slots; const struct drm_display_mode *adjusted_mode = &pipe_config->base.adjusted_mode; int mst_pbn; - bool reduce_m_n = drm_dp_has_quirk(&intel_dp->desc, - DP_DPCD_QUIRK_LIMITED_M_N); + bool constant_n = drm_dp_has_quirk(&intel_dp->desc, + DP_DPCD_QUIRK_CONSTANT_N); if (adjusted_mode->flags & DRM_MODE_FLAG_DBLSCAN) return false; @@ -87,7 +87,7 @@ static bool intel_dp_mst_compute_config(struct intel_encoder *encoder, adjusted_mode->crtc_clock, pipe_config->port_clock, &pipe_config->dp_m_n, - reduce_m_n); + constant_n); pipe_config->dp_m_n.tu = slots; diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h index 05cc31b5db16..f59359e42428 100644 --- a/include/drm/drm_dp_helper.h +++ b/include/drm/drm_dp_helper.h @@ -1260,12 +1260,12 @@ int drm_dp_read_desc(struct drm_dp_aux *aux, struct drm_dp_desc *desc, */ enum drm_dp_quirk { /** - * @DP_DPCD_QUIRK_LIMITED_M_N: + * @DP_DPCD_QUIRK_CONSTANT_N: * * The device requires main link attributes Mvid and Nvid to be limited - * to 16 bits. + * to 16 bits. So will give a constant value (0x8000) for compatability. */ - DP_DPCD_QUIRK_LIMITED_M_N, + DP_DPCD_QUIRK_CONSTANT_N, }; /**