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 F0AFDC88E4C for ; Fri, 11 Sep 2026 11:28:11 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 6E33D10EBBE; Fri, 11 Sep 2026 11:28:11 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="Ll3cxe8T"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.14]) by gabe.freedesktop.org (Postfix) with ESMTPS id 5A08810E1DF; Fri, 11 Sep 2026 11:28:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1789126089; x=1820662089; h=from:to:cc:subject:in-reply-to:references:date: message-id:mime-version; bh=hrEs4U6Q+syvfR7cUl86ZhV2S5oc+dfSBbjL+spcdHg=; b=Ll3cxe8TDJApErSQkGApxtEy7fEDl3LONxkQS3EYnBG9fbqm0LUFMjfX TX42MlNlVuIi1wNQ+/dmcfTYyITXKeh/Ornqm+otjHrsHnjceNW4KFp36 F9TrofQ0CC6uLSTZZcFPBc4iQP3L3FIENQfjk+1sWf1i9OnEikWQi6BA9 ZV6lZyttnlmpKvxC5Q80Bl6YjOW92odcwoBh1K8UXjfHg45TdBZNfy64v UDkiQRP2eebnlMlro6aocS1DPY+anf3Jf3haMraxJoQWL7PIyG1RXNf1s dybT3oQNE4YygY1RVE+dy+EzW4rSR3kTcjuPEI9766fscN8KF9pgItAC2 w==; X-CSE-ConnectionGUID: CeyJwxbWStqL7dOOYbidsA== X-CSE-MsgGUID: le33e+2VRp6/KeGv5+Jqxw== X-IronPort-AV: E=McAfee;i="6800,10657,11901"; a="89602524" X-IronPort-AV: E=Sophos;i="6.27,97,1787036400"; d="scan'208";a="89602524" Received: from fmviesa005.fm.intel.com ([10.60.135.145]) by fmvoesa108.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Sep 2026 04:28:09 -0700 X-CSE-ConnectionGUID: QxV1l6EKSGyejdeS3vfsLg== X-CSE-MsgGUID: exXt2ATSR0al+NKwH5ClaA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.27,97,1787036400"; d="scan'208";a="277147550" Received: from ettammin-mobl3.ger.corp.intel.com (HELO localhost) ([10.245.244.127]) by fmviesa005-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Sep 2026 04:28:07 -0700 From: Jani Nikula To: Suraj Kandpal , intel-xe@lists.freedesktop.org, intel-gfx@lists.freedesktop.org Cc: ankit.k.nautiyal@intel.com, arun.r.murthy@intel.com, Suraj Kandpal Subject: Re: [PATCH 01/10] drm/i915/display: Add helper to compute link M/N ratio for reuse In-Reply-To: <123bd5fd897e0c5d7d956d2cc94eb8cec6d7f91c@intel.com> Organization: Intel Finland Oy - BIC 0357606-4 - c/o Alberga Business Park, 6 krs Bertel Jungin Aukio 5, 02600 Espoo, Finland References: <20260911041449.3699400-1-suraj.kandpal@intel.com> <20260911041449.3699400-2-suraj.kandpal@intel.com> <123bd5fd897e0c5d7d956d2cc94eb8cec6d7f91c@intel.com> Date: Fri, 11 Sep 2026 14:28:04 +0300 Message-ID: <7fdf17c66751d921b26c64c3ea25060fb4f9db54@intel.com> MIME-Version: 1.0 Content-Type: text/plain 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 Fri, 11 Sep 2026, Jani Nikula wrote: > On Fri, 11 Sep 2026, Suraj Kandpal wrote: >> From: Ankit Nautiyal >> >> Introduce `intel_display_get_link_m_n()` to compute the link M/N ratio > > Please drop the backticks. IMO it's just ugly fluff in commit messages. > >> based on pixel clock and link clock. This logic was previously embedded >> within `intel_link_compute_m_n()`. >> >> The new helper allows reuse of link M/N computation in other contexts >> without requiring the full data M/N calculation. >> >> No functional changes intended. >> >> Signed-off-by: Ankit Nautiyal >> Signed-off-by: Suraj Kandpal >> --- >> drivers/gpu/drm/i915/display/intel_display.c | 18 ++++++++++++++---- >> 1 file changed, 14 insertions(+), 4 deletions(-) >> >> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c >> index fc30a455bed3..b5682c196646 100644 >> --- a/drivers/gpu/drm/i915/display/intel_display.c >> +++ b/drivers/gpu/drm/i915/display/intel_display.c >> @@ -2633,13 +2633,24 @@ static void compute_m_n(u32 *ret_m, u32 *ret_n, >> intel_reduce_m_n_ratio(ret_m, ret_n); >> } >> >> +static >> +void intel_display_get_link_m_n(u32 *link_m, u32 *link_n, >> + u32 pixel_clock, >> + u32 link_clock) > > Now we have two functions: > > - intel_display_get_link_m_n() > - intel_link_compute_m_n() > > in which one is a part of the other, but the names are quite different. > > Why? Shouldn't the names be somewhat similar? > > BR, > Jani. > > >> +{ >> + u32 link_symbol_clock = intel_dp_link_symbol_clock(link_clock); Moreover, this is now DP specific. Maybe you need a different abstraction level to keep the DP link symbol clock stuff inside intel_dp.c. BR, Jani. >> + >> + compute_m_n(link_m, link_n, >> + pixel_clock, link_symbol_clock, >> + 0x80000); >> +} >> + >> void >> intel_link_compute_m_n(u16 bits_per_pixel_x16, int nlanes, >> int pixel_clock, int link_clock, >> int bw_overhead, >> struct intel_link_m_n *m_n) >> { >> - u32 link_symbol_clock = intel_dp_link_symbol_clock(link_clock); >> u32 data_m = intel_dp_effective_data_rate(pixel_clock, bits_per_pixel_x16, >> bw_overhead); >> u32 data_n = drm_dp_max_dprx_data_rate(link_clock, nlanes); >> @@ -2656,9 +2667,8 @@ intel_link_compute_m_n(u16 bits_per_pixel_x16, int nlanes, >> data_m, data_n, >> 0x8000000); >> >> - compute_m_n(&m_n->link_m, &m_n->link_n, >> - pixel_clock, link_symbol_clock, >> - 0x80000); >> + intel_display_get_link_m_n(&m_n->link_m, &m_n->link_n, >> + pixel_clock, link_clock); >> } >> >> void intel_panel_sanitize_ssc(struct intel_display *display) -- Jani Nikula, Intel