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=-16.5 required=3.0 tests=BAYES_00, 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=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 8DA28C433E0 for ; Mon, 21 Dec 2020 12:53:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4322B212CC for ; Mon, 21 Dec 2020 12:53:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725807AbgLUMxl (ORCPT ); Mon, 21 Dec 2020 07:53:41 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57094 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725806AbgLUMxl (ORCPT ); Mon, 21 Dec 2020 07:53:41 -0500 Received: from mail-out.m-online.net (mail-out.m-online.net [IPv6:2001:a60:0:28:0:1:25:1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C9980C0613D3 for ; Mon, 21 Dec 2020 04:52:45 -0800 (PST) Received: from frontend01.mail.m-online.net (unknown [192.168.8.182]) by mail-out.m-online.net (Postfix) with ESMTP id 4Czzr61JbYz1rtNH; Mon, 21 Dec 2020 13:51:50 +0100 (CET) Received: from localhost (dynscan1.mnet-online.de [192.168.6.70]) by mail.m-online.net (Postfix) with ESMTP id 4Czzr60gkWz1qr3y; Mon, 21 Dec 2020 13:51:50 +0100 (CET) X-Virus-Scanned: amavisd-new at mnet-online.de Received: from mail.mnet-online.de ([192.168.8.182]) by localhost (dynscan1.mail.m-online.net [192.168.6.70]) (amavisd-new, port 10024) with ESMTP id dtOigQ_gs3-J; Mon, 21 Dec 2020 13:51:48 +0100 (CET) X-Auth-Info: 0Q2JADJuGAhSUwo3vzdkiMKE122vBn7kd+T9X9e6wfw= Received: from [IPv6:::1] (p578adb1c.dip0.t-ipconnect.de [87.138.219.28]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.mnet-online.de (Postfix) with ESMTPSA; Mon, 21 Dec 2020 13:51:48 +0100 (CET) Subject: Re: [PATCH] spi: stm32: FIFO threshold level - fix align packet size To: Roman Guskov , linux-spi@vger.kernel.org Cc: broonie@kernel.org, alexandre.torgue@st.com, linux-stm32@st-md-mailman.stormreply.com, Amelie DELAUNAY References: <20201221123532.27272-1-rguskov@dh-electronics.com> From: Marek Vasut Message-ID: <524f6c50-b515-1f5e-8237-97e78c9875d8@denx.de> Date: Mon, 21 Dec 2020 13:51:48 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 MIME-Version: 1.0 In-Reply-To: <20201221123532.27272-1-rguskov@dh-electronics.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org On 12/21/20 1:35 PM, Roman Guskov wrote: > if cur_bpw <= 8 and xfer_len < 4 then the value of fthlv will be 1 and > SPI registers content may have been lost. > > * If SPI data register is accessed as a 16-bit register and DSIZE <= 8bit, > better to select FTHLV = 2, 4, 6 etc > > * If SPI data register is accessed as a 32-bit register and DSIZE > 8bit, > better to select FTHLV = 2, 4, 6 etc, while if DSIZE <= 8bit, > better to select FTHLV = 4, 8, 12 etc > > Signed-off-by: Roman Guskov I think this should also have the following tag: Fixes: dcbe0d84dfa5 ("spi: add driver for STM32 SPI controller") > --- > drivers/spi/spi-stm32.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/spi/spi-stm32.c b/drivers/spi/spi-stm32.c > index 9d8ceb63f7db..417c40154477 100644 > --- a/drivers/spi/spi-stm32.c > +++ b/drivers/spi/spi-stm32.c > @@ -494,9 +494,9 @@ static u32 stm32h7_spi_prepare_fthlv(struct stm32_spi *spi, u32 xfer_len) > > /* align packet size with data registers access */ > if (spi->cur_bpw > 8) > - fthlv -= (fthlv % 2); /* multiple of 2 */ > + fthlv += (fthlv % 2) ? 1 : 0; > else > - fthlv -= (fthlv % 4); /* multiple of 4 */ > + fthlv += (fthlv % 4) ? (4 - (fthlv % 4)) : 0; > > if (!fthlv) > fthlv = 1; > Reviewed-by: Marek Vasut