From patchwork Fri May 7 23:39:39 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lyude Paul X-Patchwork-Id: 12245341 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2B75EC433ED for ; Fri, 7 May 2021 23:40:15 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id D9A3961352 for ; Fri, 7 May 2021 23:40:14 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D9A3961352 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 24F776E5AE; Fri, 7 May 2021 23:40:12 +0000 (UTC) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [216.205.24.124]) by gabe.freedesktop.org (Postfix) with ESMTPS id 79CCD6E5AE for ; Fri, 7 May 2021 23:40:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1620430809; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=44HNmprcXPmATAcSg439i4zK1J+N1ZAn9wBTygcvECQ=; b=ZE7HN7wNMMKdluc4DIK3HMS5OT+QzHrnDk16MdwB+xlJSsmpNiTiZZRZ1sOeZ0LMkD8866 B/fIsII8Lp6+/aafMacz2ItAnUVfsJI4zaOqWx9pIEGfvSLmsBFYAdzD9BN/7wH9cwGUO4 eT/hLeBsOcrVFX/hI+KN7vmtU9Mfg0o= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-513-kPlmIXA-PSaSI7__z9_P0w-1; Fri, 07 May 2021 19:40:04 -0400 X-MC-Unique: kPlmIXA-PSaSI7__z9_P0w-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 9F613107ACC7; Fri, 7 May 2021 23:40:01 +0000 (UTC) Received: from Ruby.redhat.com (ovpn-112-131.rdu2.redhat.com [10.10.112.131]) by smtp.corp.redhat.com (Postfix) with ESMTP id E4BAA10016F4; Fri, 7 May 2021 23:39:58 +0000 (UTC) From: Lyude Paul To: dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, nouveau@lists.freedesktop.org Subject: [RFC v5 1/9] drm/i915/dpcd_bl: Remove redundant AUX backlight frequency calculations Date: Fri, 7 May 2021 19:39:39 -0400 Message-Id: <20210507233947.751846-2-lyude@redhat.com> In-Reply-To: <20210507233947.751846-1-lyude@redhat.com> References: <20210507233947.751846-1-lyude@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Rajeev Nandan , Jani Nikula , David Airlie , Lucas De Marchi , open list , Anshuman Gupta , greg.depoire@gmail.com, Uma Shankar , Sean Paul , Rodrigo Vivi , Dave Airlie , Gwan-gyeong Mun Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Noticed this while moving all of the VESA backlight code in i915 over to DRM helpers: it would appear that we calculate the frequency value we want to write to DP_EDP_BACKLIGHT_FREQ_SET twice even though this value never actually changes during runtime. So, let's simplify things by just caching this value in intel_panel.backlight, and re-writing it as-needed. Changes since v1: * Wrap panel->backlight.edp.vesa.pwm_freq_pre_divider in DP_EDP_BACKLIGHT_FREQ_AUX_SET_CAP check - Jani Signed-off-by: Lyude Paul Cc: Jani Nikula Cc: Dave Airlie Cc: greg.depoire@gmail.com --- .../drm/i915/display/intel_display_types.h | 1 + .../drm/i915/display/intel_dp_aux_backlight.c | 65 ++++++------------- 2 files changed, 20 insertions(+), 46 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h index 9c0adfc60c6f..7054a37363fb 100644 --- a/drivers/gpu/drm/i915/display/intel_display_types.h +++ b/drivers/gpu/drm/i915/display/intel_display_types.h @@ -311,6 +311,7 @@ struct intel_panel { union { struct { u8 pwmgen_bit_count; + u8 pwm_freq_pre_divider; } vesa; struct { bool sdr_uses_aux; diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c index 8e9ac9ba1d38..68bfe50ada59 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c +++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c @@ -373,50 +373,6 @@ intel_dp_aux_vesa_set_backlight(const struct drm_connector_state *conn_state, } } -/* - * Set PWM Frequency divider to match desired frequency in vbt. - * The PWM Frequency is calculated as 27Mhz / (F x P). - * - Where F = PWM Frequency Pre-Divider value programmed by field 7:0 of the - * EDP_BACKLIGHT_FREQ_SET register (DPCD Address 00728h) - * - Where P = 2^Pn, where Pn is the value programmed by field 4:0 of the - * EDP_PWMGEN_BIT_COUNT register (DPCD Address 00724h) - */ -static bool intel_dp_aux_vesa_set_pwm_freq(struct intel_connector *connector) -{ - struct drm_i915_private *dev_priv = to_i915(connector->base.dev); - struct intel_dp *intel_dp = intel_attached_dp(connector); - const u8 pn = connector->panel.backlight.edp.vesa.pwmgen_bit_count; - int freq, fxp, f, fxp_actual, fxp_min, fxp_max; - - freq = dev_priv->vbt.backlight.pwm_freq_hz; - if (!freq) { - drm_dbg_kms(&dev_priv->drm, - "Use panel default backlight frequency\n"); - return false; - } - - fxp = DIV_ROUND_CLOSEST(KHz(DP_EDP_BACKLIGHT_FREQ_BASE_KHZ), freq); - f = clamp(DIV_ROUND_CLOSEST(fxp, 1 << pn), 1, 255); - fxp_actual = f << pn; - - /* Ensure frequency is within 25% of desired value */ - fxp_min = DIV_ROUND_CLOSEST(fxp * 3, 4); - fxp_max = DIV_ROUND_CLOSEST(fxp * 5, 4); - - if (fxp_min > fxp_actual || fxp_actual > fxp_max) { - drm_dbg_kms(&dev_priv->drm, "Actual frequency out of range\n"); - return false; - } - - if (drm_dp_dpcd_writeb(&intel_dp->aux, - DP_EDP_BACKLIGHT_FREQ_SET, (u8) f) < 0) { - drm_dbg_kms(&dev_priv->drm, - "Failed to write aux backlight freq\n"); - return false; - } - return true; -} - static void intel_dp_aux_vesa_enable_backlight(const struct intel_crtc_state *crtc_state, const struct drm_connector_state *conn_state, u32 level) @@ -459,9 +415,13 @@ intel_dp_aux_vesa_enable_backlight(const struct intel_crtc_state *crtc_state, break; } - if (intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_FREQ_AUX_SET_CAP) - if (intel_dp_aux_vesa_set_pwm_freq(connector)) + if (panel->backlight.edp.vesa.pwm_freq_pre_divider) { + if (drm_dp_dpcd_writeb(&intel_dp->aux, DP_EDP_BACKLIGHT_FREQ_SET, + panel->backlight.edp.vesa.pwm_freq_pre_divider) == 1) new_dpcd_buf |= DP_EDP_BACKLIGHT_FREQ_AUX_SET_ENABLE; + else + drm_dbg_kms(&i915->drm, "Failed to write aux backlight frequency\n"); + } if (new_dpcd_buf != dpcd_buf) { if (drm_dp_dpcd_writeb(&intel_dp->aux, @@ -482,6 +442,14 @@ static void intel_dp_aux_vesa_disable_backlight(const struct drm_connector_state false); } +/* + * Compute PWM frequency divider value based off the frequency provided to us by the vbt. + * The PWM Frequency is calculated as 27Mhz / (F x P). + * - Where F = PWM Frequency Pre-Divider value programmed by field 7:0 of the + * EDP_BACKLIGHT_FREQ_SET register (DPCD Address 00728h) + * - Where P = 2^Pn, where Pn is the value programmed by field 4:0 of the + * EDP_PWMGEN_BIT_COUNT register (DPCD Address 00724h) + */ static u32 intel_dp_aux_vesa_calc_max_backlight(struct intel_connector *connector) { struct drm_i915_private *i915 = to_i915(connector->base.dev); @@ -533,8 +501,10 @@ static u32 intel_dp_aux_vesa_calc_max_backlight(struct intel_connector *connecto pn_min &= DP_EDP_PWMGEN_BIT_COUNT_MASK; pn_max &= DP_EDP_PWMGEN_BIT_COUNT_MASK; + /* Ensure frequency is within 25% of desired value */ fxp_min = DIV_ROUND_CLOSEST(fxp * 3, 4); fxp_max = DIV_ROUND_CLOSEST(fxp * 5, 4); + if (fxp_min < (1 << pn_min) || (255 << pn_max) < fxp_max) { drm_dbg_kms(&i915->drm, "VBT defined backlight frequency out of range\n"); @@ -555,7 +525,10 @@ static u32 intel_dp_aux_vesa_calc_max_backlight(struct intel_connector *connecto "Failed to write aux pwmgen bit count\n"); return max_backlight; } + panel->backlight.edp.vesa.pwmgen_bit_count = pn; + if (intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_FREQ_AUX_SET_CAP) + panel->backlight.edp.vesa.pwm_freq_pre_divider = f; max_backlight = (1 << pn) - 1;