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=-17.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 D8F30C433E0 for ; Wed, 10 Mar 2021 07:22:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9BE4064FF2 for ; Wed, 10 Mar 2021 07:22:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230422AbhCJHVe (ORCPT ); Wed, 10 Mar 2021 02:21:34 -0500 Received: from www381.your-server.de ([78.46.137.84]:60428 "EHLO www381.your-server.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229574AbhCJHVW (ORCPT ); Wed, 10 Mar 2021 02:21:22 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=metafoo.de; s=default2002; h=Content-Transfer-Encoding:Content-Type:In-Reply-To: MIME-Version:Date:Message-ID:From:References:Cc:To:Subject:Sender:Reply-To: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID; bh=qz+v/U8OfCpTcBxQ524rjA3+edB4w4v2XAKWVao9tZw=; b=NOcAydZc5yBZM0Muwj7fz+C8N6 MLVX5u/dL4dKLslXt9sIydO9khfqiXZy8yYjcv1kT6LDVjL/8hiWkYVoIrzv4E/HCeSH7Qjdz3Fa0 jVoOH/9yqvIniidnNF7Nsziu54b/eKK9jz9QFQVAO2ICDFZypDI04wgSKrt1D5SX06TIqupGjiq6y d/71t5fC8hQOTrGNz6/jHWJmo37Ix9C6lsRdQx8RKT+nwmWuuCdc8beN5t4DnJemOfoxj8mzUEYlh XWZvpdDGVsG/PFnkQFgSwOylKlq7ODZf4TnzXtJn691AbSdy+LIzbbdsAJlFF4pFr1zkpUDM83kqI /BUNDg1g==; Received: from sslproxy03.your-server.de ([88.198.220.132]) by www381.your-server.de with esmtpsa (TLSv1.3:TLS_AES_256_GCM_SHA384:256) (Exim 4.92.3) (envelope-from ) id 1lJt9f-0001ZM-Fz; Wed, 10 Mar 2021 08:21:15 +0100 Received: from [62.216.202.180] (helo=[192.168.178.20]) by sslproxy03.your-server.de with esmtpsa (TLSv1.3:TLS_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1lJt9f-00041w-55; Wed, 10 Mar 2021 08:21:15 +0100 Subject: Re: [PATCH 01/10] spi: spi-axi-spi-engine: remove usage of delay_usecs To: Alexandru Ardelean Cc: linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org, greybus-dev@lists.linaro.org, devel@driverdev.osuosl.org, linux-tegra@vger.kernel.org, bcm-kernel-feedback-list@broadcom.com, broonie@kernel.org, gregkh@linuxfoundation.org, elder@kernel.org, johan@kernel.org, vireshk@kernel.org, rmfrfs@gmail.com, f.fainelli@gmail.com, ldewangan@nvidia.com, thierry.reding@gmail.com, jonathanh@nvidia.com, linux@deviqon.com References: <20210308145502.1075689-1-aardelean@deviqon.com> <20210308145502.1075689-2-aardelean@deviqon.com> <8a6ec9a1-71f8-ce1d-600a-66eba9244a54@metafoo.de> From: Lars-Peter Clausen Message-ID: Date: Wed, 10 Mar 2021 08:21:14 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US X-Authenticated-Sender: lars@metafoo.de X-Virus-Scanned: Clear (ClamAV 0.102.4/26103/Tue Mar 9 13:03:37 2021) Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org On 3/10/21 8:16 AM, Alexandru Ardelean wrote: > On Mon, 8 Mar 2021 at 18:42, Lars-Peter Clausen wrote: >> On 3/8/21 3:54 PM, Alexandru Ardelean wrote: >>> The 'delay_usecs' field was handled for backwards compatibility in case >>> there were some users that still configured SPI delay transfers with >>> this field. >>> >>> They should all be removed by now. >>> >>> Signed-off-by: Alexandru Ardelean >>> --- >>> drivers/spi/spi-axi-spi-engine.c | 12 ++++-------- >>> 1 file changed, 4 insertions(+), 8 deletions(-) >>> >>> diff --git a/drivers/spi/spi-axi-spi-engine.c b/drivers/spi/spi-axi-spi-engine.c >>> index af86e6d6e16b..80c3e38f5c1b 100644 >>> --- a/drivers/spi/spi-axi-spi-engine.c >>> +++ b/drivers/spi/spi-axi-spi-engine.c >>> @@ -170,14 +170,10 @@ static void spi_engine_gen_sleep(struct spi_engine_program *p, bool dry, >>> unsigned int t; >>> int delay; >>> >>> - if (xfer->delay_usecs) { >>> - delay = xfer->delay_usecs; >>> - } else { >>> - delay = spi_delay_to_ns(&xfer->delay, xfer); >>> - if (delay < 0) >>> - return; >>> - delay /= 1000; >>> - } >>> + delay = spi_delay_to_ns(&xfer->delay, xfer); >>> + if (delay < 0) >>> + return; >> Bit of a nit, but this could be `delay <= 0` and then drop the check for >> `delay == 0` below. > hmm, that's a bit debatable, because the `delay == 0` check comes > after `delay /= 1000` ; > to do what you're suggesting, it would probably need a > DIV_ROUND_UP(delay, 1000) to make sure that even sub-microsecond > delays don't become zero; Ah, true. Lets keep the code as it is. On the other hand you could argue that we should round up to ensure the delay is at least as long as requested. But that is something that should be changed independently from this series.