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 57780CD6E4A for ; Fri, 29 May 2026 15:20:19 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id DD7CF1120CB; Fri, 29 May 2026 15:20:18 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="VM5aWSLY"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.10]) by gabe.freedesktop.org (Postfix) with ESMTPS id 0C03A112091; Fri, 29 May 2026 15:20:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1780068017; x=1811604017; h=date:from:to:cc:subject:message-id:references: mime-version:content-transfer-encoding:in-reply-to; bh=Fnrjs5jZUpdBPRWc6JXyIiZppYLdne+fYJqBBLOuC9Y=; b=VM5aWSLYKtWyYylYwO5UVtBXcyayY8AwRcjvfftykYdrWYCvoqVv1S3q E3Muf5UfE+TFfitFXSDm+EKnv/jQ3Ec7ueWk43vh824sHiZZWfQu+al1K A4ofprYeDsW/QaUirvpitdSsRGYRVbSn2qa39ZxX8fT7ev043uHSFzLbl uYBw1zqLmJwj6fSSBk4+S78X3ghqifbCmwTD7MF86sO+pb8LrKs2t7vqC EqFf+uJHvZAVEDZ80tKi2Uv7omc5Vw1MxcZFJUJGL+M9z5WvmQ/EFAAaq 4wJKOQ03zMJSeNH8p0VMnixnfxYA4nDOQILouxFBUg31CS3eTOZW/kz18 Q==; X-CSE-ConnectionGUID: YMU1Nyw2TP2BESCQhYZH6w== X-CSE-MsgGUID: Cv62znIgQXSysvpznIDhbw== X-IronPort-AV: E=McAfee;i="6800,10657,11801"; a="98338710" X-IronPort-AV: E=Sophos;i="6.24,175,1774335600"; d="scan'208";a="98338710" Received: from orviesa004.jf.intel.com ([10.64.159.144]) by orvoesa102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 May 2026 08:20:10 -0700 X-CSE-ConnectionGUID: 3mCMpy6dQJyUTeK1grrrUA== X-CSE-MsgGUID: 8wT2o0+VQ+GH1pnj6fQq5A== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.24,175,1774335600"; d="scan'208";a="247162431" Received: from pgcooper-mobl3.ger.corp.intel.com (HELO localhost) ([10.245.244.182]) by orviesa004-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 29 May 2026 08:20:08 -0700 Date: Fri, 29 May 2026 18:20:04 +0300 From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= To: Jani Nikula Cc: Vinod Govindapillai , intel-xe@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, ville.syrjala@intel.com, matthew.d.roper@intel.com, shawn.c.lee@intel.com Subject: Re: [PATCH] drm/i915/display: update BW buddy initialization for LPDDR4 and LPDDR5 Message-ID: References: <20260528182601.205595-1-vinod.govindapillai@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-Patchwork-Hint: comment Organization: Intel Finland Oy - BIC 0357606-4 - c/o Alberga Business Park, 6 krs Bertel Jungin Aukio 5, 02600 Espoo, Finland 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, May 29, 2026 at 04:39:13PM +0300, Jani Nikula wrote: > On Thu, 28 May 2026, Vinod Govindapillai wrote: > > Pcode reports the number of subchannels for LPDDR4 and LPDDR5. > > But the page mask selection table is based on the channels. So > > adjust the number of channels for LPDDR4 and LPDDR5 so that the > > correct page mask can be picked. There are two subchannels per > > channel. > > IMO the parsing of the information belongs in intel_dram.c. If you get > subchannels from pcode or where ever, intel_dram.c should figure it out, > and store the number of channels in ->num_channels. We actually want subchannels for QGV stuff. And that's what modern pcode gives us, older pcode gave us channels instead and we convert that to subchannels in the QGV code on those platforms. I have a patch to move the adjustment into intel_dram.c for those platforms so that we get consistent data out of intel_dram.c everywhere. For this thing here I think the best thing would be to change the table to use subchannels instead. Looks like Vinod didn't file the Bspec issue asking for the table to be updated there, so I just did that. -- Ville Syrjälä Intel