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=-7.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 067E3C433E0 for ; Sat, 6 Feb 2021 00:07:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BCB3D65011 for ; Sat, 6 Feb 2021 00:07:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231273AbhBFAHh (ORCPT ); Fri, 5 Feb 2021 19:07:37 -0500 Received: from mail.kernel.org ([198.145.29.99]:48684 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229704AbhBENbO (ORCPT ); Fri, 5 Feb 2021 08:31:14 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 9C37164F6C; Fri, 5 Feb 2021 13:30:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1612531832; bh=8/S6dC/Cyik2IWPqPhmn7AbHJFdhxexop0d79CYhEaM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ZDo8YhqUJAJClF4NCrCvU51d0X/24FNmGuc0WrS7hydeqAjgKGxWXl9Q7DDS+azbK h7jMc1pTK0KpZMBFmCqkALv4BP3/Ecj5DZcuFDbqSTuKtxKMJWNGyIbzVn0SkQigD8 gp9T1MyYldNhUKKOBseQ98FqH4SjtWD3WrI+djoINV/+FQeKBVXL/BeQoi2mEWDGXL jBvN7GQQaI1D4Gwm8xOIYoBJg379wlh+R78xtQZa53ceASYjbpc1bnSJBzHwNEbv43 OwGAh1/ZTYcMWaYXqPGG2mUXDQZHnzkWWgDzKjxzJxyYt53lCpp+x0axXfe2HRxfCY j56FQMdzg+Qyg== Date: Fri, 5 Feb 2021 13:29:42 +0000 From: Mark Brown To: Alain Volmat Cc: amelie.delaunay@foss.st.com, mcoquelin.stm32@gmail.com, alexandre.torgue@foss.st.com, linux-spi@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, fabrice.gasnier@foss.st.com Subject: Re: [PATCH 1/8] spi: stm32: properly handle 0 byte transfer Message-ID: <20210205132942.GA4720@sirena.org.uk> References: <1612523342-10466-1-git-send-email-alain.volmat@foss.st.com> <1612523342-10466-2-git-send-email-alain.volmat@foss.st.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="3V7upXqbjpZ4EhLz" Content-Disposition: inline In-Reply-To: <1612523342-10466-2-git-send-email-alain.volmat@foss.st.com> X-Cookie: Huh? User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --3V7upXqbjpZ4EhLz Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Fri, Feb 05, 2021 at 12:08:55PM +0100, Alain Volmat wrote: > On 0 byte transfer request, return straight from the > xfer function after finalizing the transfer. > + if (transfer->len == 0) { > + spi_finalize_current_transfer(master); > + return 0; The driver only needs to finalize the transfer if it returned a value greater than 0, returning 0 indicates that the transfer is already done. --3V7upXqbjpZ4EhLz Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAmAdSEUACgkQJNaLcl1U h9DG6gf+Pkz5r4YOP6ld6ZsZdM/LuqTjO92jsCER31Xl2O8S1A2Tgfj1La0v40tE 2GBWz1gdoIam2hxKE3HYTIqB/952V5ETUMekujRNnFQq4mRn1oxaaD8z85LWqAxB OUDkBLLVch560M5MUfZxYMydbd+DbZrbR4K1XE/oTB+Sn79XNQtKrClK6ytHjnbW XDtHWh+zlm12jj5qm160n0takkQaEYkAdYxE8C5imuRhk+OXsgrqoYOLTehde0hp nBkaLiBVsup7XbOMmbpkH1hEKk9GEwmn46Q3S9TnkUYblsdAaGYGRtA/m0XEy2nA QFJBlfHf6+dAAXVb4YaWxPp/Q8S5QA== =ad7+ -----END PGP SIGNATURE----- --3V7upXqbjpZ4EhLz--