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 9B0E4C79F8C for ; Wed, 9 Sep 2026 07:48:41 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 0A72E10EFAE; Wed, 9 Sep 2026 07:48:41 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="DkXHcbFz"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.15]) by gabe.freedesktop.org (Postfix) with ESMTPS id E056910EF93; Wed, 9 Sep 2026 07:48:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1788940118; x=1820476118; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=ADhni/y26ZrlgoHuaN8kFwhh051HfF292qgcQaWpdn8=; b=DkXHcbFz+tO0uEel30bxJSCkIItRq8DQReeD026LeHCpOHHw+WNKm8hz X5cDXxP9uYpiJBlM9K8FqFBPLf+VEd++pq3XGYUsE8QBXlByNSa3iyu25 FOmJa1Rn4SM+mNU00J3uXQ6EvuCUEPb6SvktSTy1Uzjm+IWl9gJVPJFmK c3tQCTojZrXF5C5F8BTFeEMYZuXPPWSeT4BkJl0DnJbHv5ck1gytqCcl6 kwgUQUJ9tEgM5QxedAAp6GgHID35Tb3jxKCUx+Gv8fpj4y/EIPQM2zXMd 0pbmd6nqzBMKL+zX1YJey4Yi/q3Bu1D9NKCJpgzGbezxe79LWuBGgEuAA Q==; X-CSE-ConnectionGUID: tM1fjBXvQjqAvPzp+BtOHA== X-CSE-MsgGUID: XbRxFqzORZOzcsRij8F/gw== X-IronPort-AV: E=McAfee;i="6800,10657,11900"; a="89480431" X-IronPort-AV: E=Sophos;i="6.25,270,1779174000"; d="scan'208";a="89480431" Received: from fmviesa008.fm.intel.com ([10.60.135.148]) by fmvoesa109.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Sep 2026 00:48:17 -0700 X-CSE-ConnectionGUID: MwgmjvQ7TvG3suKRmR6ZZg== X-CSE-MsgGUID: qupB5NXrSQmalrMnMDDjSA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.25,270,1779174000"; d="scan'208";a="268680933" Received: from cfl-desktop.iind.intel.com ([10.190.239.20]) by fmviesa008.fm.intel.com with ESMTP; 09 Sep 2026 00:48:15 -0700 From: Uma Shankar To: intel-gfx@lists.freedesktop.org, intel-xe@lists.freedesktop.org, dibin.moolakadan.subrahmanian@intel.com, ramanaidu.naladala@intel.com Cc: Uma Shankar Subject: [v5 4/4] drm/i915/display: Gate periodic AS SDP skip frames behind a debugfs knob Date: Wed, 9 Sep 2026 13:38:10 +0530 Message-ID: <20260909080810.2202879-5-uma.shankar@intel.com> X-Mailer: git-send-email 2.50.1 In-Reply-To: <20260909080810.2202879-1-uma.shankar@intel.com> References: <20260909080810.2202879-1-uma.shankar@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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" Periodic AS SDP (skip frames) drives a Panel Replay panel down toward its minimum refresh rate. It is a new, panel- and platform-sensitive behaviour, so keep it opt-in rather than enabling it unconditionally. Expose it as a per-device debugfs knob, enable_periodic_assdp, rather than a module parameter. The behaviour is panel-specific, so the correct granularity is per-device, not per-module. The knob is added through the intel_display_params infrastructure (shared by i915 and xe) with a debugfs entry only. It defaults to false (feature disabled); write 1 to the debugfs file to enable periodic AS SDP at runtime. Gate the feature at its single choke point, intel_pr_as_sdp_skip_frames(): returning a zero skip count when the knob is off makes both the PR_ALPM_CTL programming (intel_alpm_configure_pr_as_sdp()) and the DC3co force-disable predicate (intel_alpm_pr_as_sdp_skip_frames_enabled()) a no-op, so AS SDP continues to be sent on every frame as before. v2: Switch to debugfs entry and drop module param Assisted-by: Claude:claude-opus-4-8 Signed-off-by: Uma Shankar Reviewed-by: Dibin Moolakadan Subrahmanian Tested-by: Naladala Ramanaidu --- drivers/gpu/drm/i915/display/intel_alpm.c | 5 +++++ drivers/gpu/drm/i915/display/intel_display_params.h | 5 +++++ 2 files changed, 10 insertions(+) diff --git a/drivers/gpu/drm/i915/display/intel_alpm.c b/drivers/gpu/drm/i915/display/intel_alpm.c index c784e77f610b..10943539bc7c 100644 --- a/drivers/gpu/drm/i915/display/intel_alpm.c +++ b/drivers/gpu/drm/i915/display/intel_alpm.c @@ -392,11 +392,16 @@ static u32 get_pr_alpm_as_sdp_transmission_time(const struct intel_crtc_state *c */ static u32 intel_pr_as_sdp_skip_frames(struct intel_dp *intel_dp) { + struct intel_display *display = to_intel_display(intel_dp); const struct drm_display_info *info = &intel_dp->attached_connector->base.display_info; int max_vrefresh = info->monitor_range.max_vfreq; int min_vrefresh = info->monitor_range.min_vfreq; + /* Off by default; gated by the enable_periodic_assdp debugfs knob. */ + if (!display->params.enable_periodic_assdp) + return 0; + if (min_vrefresh <= 0 || max_vrefresh <= min_vrefresh) return 0; diff --git a/drivers/gpu/drm/i915/display/intel_display_params.h b/drivers/gpu/drm/i915/display/intel_display_params.h index b95ecf728daa..ba01aeaf8944 100644 --- a/drivers/gpu/drm/i915/display/intel_display_params.h +++ b/drivers/gpu/drm/i915/display/intel_display_params.h @@ -50,6 +50,11 @@ struct drm_printer; param(bool, psr_safest_params, false, 0400) \ param(bool, enable_psr2_sel_fetch, true, 0400) \ param(int, enable_dmc_wl, -1, 0400) \ + /* + * Debugfs-only knob (per-device): no matching module_param is registered + * in intel_display_params.c on purpose. Runtime-toggle via debugfs. + */ \ + param(bool, enable_periodic_assdp, false, 0600) \ #define MEMBER(T, member, ...) T member; struct intel_display_params { -- 2.50.1