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 34DBEC4332F for ; Tue, 14 Nov 2023 09:00:57 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id A4D0310E1DA; Tue, 14 Nov 2023 09:00:56 +0000 (UTC) Received: from mgamail.intel.com (mgamail.intel.com [134.134.136.24]) by gabe.freedesktop.org (Postfix) with ESMTPS id D9DCC10E1DA for ; Tue, 14 Nov 2023 09:00:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1699952453; x=1731488453; h=from:to:subject:in-reply-to:references:date:message-id: mime-version; bh=VA8mFzE3K3idJ7LQjjAQ4jNNWc5gxOacPziaLlRcM8U=; b=FRKoX3zyxzDos6Zk9IwTPCw4bCy3acqlfC1CtwoKlPB1FQkSWMgcjIIs 6oIAqB1HMtQEjvgKZuO8Cazc5EtuKkI6KxZ7PIURRMHoF5ArGAPn2jkk5 YZ5QbGHSrcbAUrbSCjMKuCVrDk9yY/SodS6p+dnEFMpDZKG3OjYvx5J4r sgwZB/wpKkB8XjQ5g6/WCehkcmTJMgiNpD9W4jV99M0GGTQJqVLrDF5kb xQ51vAcoOnng9t/7FepJKOyh9kGyX2/Hkg1tK0oQv+PBe5/qBFXlw//mY qvWAdRRZYBHq8RPvLEW0Cgm/ekOpmCo0kRP6MdfW+lVgLC1+XWo4AUGIr A==; X-IronPort-AV: E=McAfee;i="6600,9927,10893"; a="393472359" X-IronPort-AV: E=Sophos;i="6.03,301,1694761200"; d="scan'208";a="393472359" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Nov 2023 01:00:53 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10893"; a="793713391" X-IronPort-AV: E=Sophos;i="6.03,301,1694761200"; d="scan'208";a="793713391" Received: from hatran1-mobl1.ccr.corp.intel.com (HELO localhost) ([10.252.56.145]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Nov 2023 01:00:52 -0800 From: Jani Nikula To: Imre Deak , intel-gfx@lists.freedesktop.org In-Reply-To: <20231113201110.510724-1-imre.deak@intel.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo References: <20231113201110.510724-1-imre.deak@intel.com> Date: Tue, 14 Nov 2023 11:00:49 +0200 Message-ID: <87v8a4so8u.fsf@intel.com> MIME-Version: 1.0 Content-Type: text/plain Subject: Re: [Intel-gfx] [PATCH 1/4] drm/i915/dp: Account for channel coding efficiency on UHBR links 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 Mon, 13 Nov 2023, Imre Deak wrote: > Apply the correct BW allocation overhead and channel coding efficiency > on UHBR link rates, similarly to DP1.4 link rates. > > Signed-off-by: Imre Deak > --- > drivers/gpu/drm/i915/display/intel_display.c | 10 ---------- > 1 file changed, 10 deletions(-) > > diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c > index 3effafcbb411a..24aebdb715e7d 100644 > --- a/drivers/gpu/drm/i915/display/intel_display.c > +++ b/drivers/gpu/drm/i915/display/intel_display.c > @@ -2398,16 +2398,6 @@ add_bw_alloc_overhead(int link_clock, int bw_overhead, > int ch_coding_efficiency = > drm_dp_bw_channel_coding_efficiency(is_uhbr); Why do we have this and intel_dp_max_data_rate() separately? BR, Jani. > > - /* > - * TODO: adjust for actual UHBR channel coding efficiency and BW > - * overhead. > - */ > - if (is_uhbr) { > - *data_m = pixel_data_rate; > - *data_n = link_data_rate * 8 / 10; > - return; > - } > - > *data_m = DIV_ROUND_UP_ULL(mul_u32_u32(pixel_data_rate, bw_overhead), > 1000000); > *data_n = DIV_ROUND_DOWN_ULL(mul_u32_u32(link_data_rate, ch_coding_efficiency), -- Jani Nikula, Intel