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 X-Spam-Level: X-Spam-Status: No, score=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DFCDDC10DCE for ; Thu, 12 Mar 2020 11:39:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BD23B206E7 for ; Thu, 12 Mar 2020 11:39:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726946AbgCLLjo (ORCPT ); Thu, 12 Mar 2020 07:39:44 -0400 Received: from mga18.intel.com ([134.134.136.126]:29762 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725268AbgCLLjn (ORCPT ); Thu, 12 Mar 2020 07:39:43 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga003.jf.intel.com ([10.7.209.27]) by orsmga106.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 12 Mar 2020 04:39:42 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,544,1574150400"; d="scan'208";a="242995404" Received: from swaydand-mobl1.amr.corp.intel.com (HELO [10.255.230.33]) ([10.255.230.33]) by orsmga003.jf.intel.com with ESMTP; 12 Mar 2020 04:39:41 -0700 Subject: Re: [PATCH] soundwire: stream: use sdw_write instead of update To: Srinivas Kandagatla , vkoul@kernel.org Cc: linux-kernel@vger.kernel.org, alsa-devel@alsa-project.org References: <20200312100105.5293-1-srinivas.kandagatla@linaro.org> From: Pierre-Louis Bossart Message-ID: Date: Thu, 12 Mar 2020 05:45:32 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.4.1 MIME-Version: 1.0 In-Reply-To: <20200312100105.5293-1-srinivas.kandagatla@linaro.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 3/12/20 5:01 AM, Srinivas Kandagatla wrote: > There is no point in using update for registers with write mask > as 0xFF, this adds unecessary traffic on the bus. > Just use sdw_write directly. well in theory you could have two streams share the same port, that's allowed by the specification. But since it clearly documented as not supported /* * Since bus doesn't support sharing a port across two streams, * it is safe to reset this register */ this mask handing is indeed completely overkill. Acked-by: Pierre-Louis Bossart > > Signed-off-by: Srinivas Kandagatla > --- > drivers/soundwire/stream.c | 9 ++++----- > 1 file changed, 4 insertions(+), 5 deletions(-) > > diff --git a/drivers/soundwire/stream.c b/drivers/soundwire/stream.c > index 00348d1fc606..1b43d03c79ea 100644 > --- a/drivers/soundwire/stream.c > +++ b/drivers/soundwire/stream.c > @@ -313,9 +313,9 @@ static int sdw_enable_disable_slave_ports(struct sdw_bus *bus, > * it is safe to reset this register > */ > if (en) > - ret = sdw_update(s_rt->slave, addr, 0xFF, p_rt->ch_mask); > + ret = sdw_write(s_rt->slave, addr, p_rt->ch_mask); > else > - ret = sdw_update(s_rt->slave, addr, 0xFF, 0x0); > + ret = sdw_write(s_rt->slave, addr, 0x0); > > if (ret < 0) > dev_err(&s_rt->slave->dev, > @@ -464,10 +464,9 @@ static int sdw_prep_deprep_slave_ports(struct sdw_bus *bus, > addr = SDW_DPN_PREPARECTRL(p_rt->num); > > if (prep) > - ret = sdw_update(s_rt->slave, addr, > - 0xFF, p_rt->ch_mask); > + ret = sdw_write(s_rt->slave, addr, p_rt->ch_mask); > else > - ret = sdw_update(s_rt->slave, addr, 0xFF, 0x0); > + ret = sdw_write(s_rt->slave, addr, 0x0); > > if (ret < 0) { > dev_err(&s_rt->slave->dev, >