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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5FA1CC38142 for ; Mon, 23 Jan 2023 16:50:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232528AbjAWQuF (ORCPT ); Mon, 23 Jan 2023 11:50:05 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55042 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233520AbjAWQuB (ORCPT ); Mon, 23 Jan 2023 11:50:01 -0500 Received: from mx0b-001ae601.pphosted.com (mx0b-001ae601.pphosted.com [67.231.152.168]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C43EB2943F for ; Mon, 23 Jan 2023 08:50:00 -0800 (PST) Received: from pps.filterd (m0077474.ppops.net [127.0.0.1]) by mx0b-001ae601.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 30N91JmA009174; Mon, 23 Jan 2023 10:49:51 -0600 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cirrus.com; h=from : to : cc : subject : date : message-id : mime-version : content-transfer-encoding : content-type; s=PODMain02222019; bh=EEhuc1uSnv3B2TkErgB0IZM1Fy5T36RVXG2x8hfUnXE=; b=hBFPFsymmu3H+/BHZj3a529128yyGXpK8EB+hgapYnvSQKMhHyJqLf5KrYRjcCeZqjU7 em+qzvG0wW0CKavGbkXclYwnxJUEFawB9BDF0/apmiikl7VOgSu1FmR1ZJOU9mX8muQQ PDe+7w3pTHh0fUySXP0MWWgqwTGHEfYqPve9Q9C4RJig9U2rnVK7uTRRzgESpGcOznZJ 4JCQ0o6UMEsmZLYrolRfmg0Id+HTUv/kGVsH+2je397tmFhgWqZNGhaJLIjy68aMaf+8 d5X1t4vjxlJl9hh+17iOfYshunl7WFKys8HJ1fcGLv1XrJiUdejOvmnJsEHLwYSpDKQt 2w== Received: from ediex01.ad.cirrus.com ([84.19.233.68]) by mx0b-001ae601.pphosted.com (PPS) with ESMTPS id 3n8dbsknrn-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 23 Jan 2023 10:49:51 -0600 Received: from ediex01.ad.cirrus.com (198.61.84.80) by ediex01.ad.cirrus.com (198.61.84.80) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1118.21; Mon, 23 Jan 2023 10:49:49 -0600 Received: from ediswmail.ad.cirrus.com (198.61.86.93) by ediex01.ad.cirrus.com (198.61.84.80) with Microsoft SMTP Server id 15.2.1118.21 via Frontend Transport; Mon, 23 Jan 2023 10:49:49 -0600 Received: from edi-sw-dsktp-006.ad.cirrus.com (edi-sw-dsktp-006.ad.cirrus.com [198.90.251.127]) by ediswmail.ad.cirrus.com (Postfix) with ESMTP id 460382C5; Mon, 23 Jan 2023 16:49:49 +0000 (UTC) From: Richard Fitzgerald To: , , , CC: , , , Richard Fitzgerald Subject: [PATCH v2 0/2] soundwire: Remove redundant zeroing of page registers Date: Mon, 23 Jan 2023 16:49:47 +0000 Message-ID: <20230123164949.245898-1-rf@opensource.cirrus.com> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-Proofpoint-ORIG-GUID: G-ubMUt4tlVURYgmRyjxWCcoLjCi4wnn X-Proofpoint-GUID: G-ubMUt4tlVURYgmRyjxWCcoLjCi4wnn X-Proofpoint-Spam-Reason: safe Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Writing zero to the page registers after each message transaction can add up to a lot of overhead for codecs that need to transfer large amount of data - for example a firmware download. There's no spec reason I can see for this zeroing. The page registers are only used for a paged address. The bus code uses a non-paged address for registers in page 0. It always writes the page registers at the start of a paged transaction. If this zeroing was a workaround for anything, let me know and I will re-implement the zeroing as a quirk that can be enabled only when it is necessary. Changes since v1: - Reworded the commit message to patch #1: - say that this is for devices that support paging - mention bit 15 as the paging flag - split a long sentence into two sentences. No code changes. Richard Fitzgerald (2): soundwire: bus: Don't zero page registers after every transaction soundwire: bus: Remove unused reset_page_addr() callback drivers/soundwire/bus.c | 23 ----------------------- drivers/soundwire/cadence_master.c | 14 -------------- drivers/soundwire/cadence_master.h | 3 --- drivers/soundwire/intel_auxdevice.c | 1 - include/linux/soundwire/sdw.h | 3 --- 5 files changed, 44 deletions(-) -- 2.30.2