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=-2.6 required=3.0 tests=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 85574C433E2 for ; Fri, 22 May 2020 11:36:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5F2A5206D5 for ; Fri, 22 May 2020 11:36:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590147399; bh=z/6OXOepRElS/C2Gkk6RRZeDF9+60BoN0+lQKMHv4sc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=G3HZP1l39MI/pzux3jb7+k1qk/wNUcTHtsIwF4pHc3GiGBa7xrF0D0SRqyNsdWS9o W/T8bqoeM+Dr+KNKbYzlHj2A0DX9aGbRJ/A6UyREfj/b0T31X35NDhAwfYcSdYjPo+ DNgrEBBWXQ5WXB6SQnwYO8wV2iuq70Kc6L0DeKOc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729805AbgEVLgi (ORCPT ); Fri, 22 May 2020 07:36:38 -0400 Received: from mail.kernel.org ([198.145.29.99]:42818 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728465AbgEVLgh (ORCPT ); Fri, 22 May 2020 07:36:37 -0400 Received: from localhost (fw-tnat.cambridge.arm.com [217.140.96.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id A6CF8206C3; Fri, 22 May 2020 11:36:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590147397; bh=z/6OXOepRElS/C2Gkk6RRZeDF9+60BoN0+lQKMHv4sc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=SViwwqlJ87aevdHn4RYwBdrJnJkpk2rgiCE7e168UaD8MlGXvEupOGhOH7ejYfrbJ N3kZOSYajFR+FWCWBWyZDHjCeSTW6pHxtLB0BJj1sTzEGGQE0HGaQz/KalAcMtdjVw a7j7/Lewv8pBtYtgHXcvbty7bFHiOt4Q0y6gEdzA= Date: Fri, 22 May 2020 12:36:34 +0100 From: Mark Brown To: dillon.minfei@gmail.com Cc: robh+dt@kernel.org, p.zabel@pengutronix.de, mcoquelin.stm32@gmail.com, devicetree@vger.kernel.org, alexandre.torgue@st.com, thierry.reding@gmail.com, sam@ravnborg.org, airlied@linux.ie, daniel@ffwll.ch, mturquette@baylibre.com, sboyd@kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-spi@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, dri-devel@lists.freedesktop.org, linux-clk@vger.kernel.org Subject: Re: [PATCH v4 3/8] spi: stm32: Add 'SPI_SIMPLEX_RX', 'SPI_3WIRE_RX' support for stm32f4 Message-ID: <20200522113634.GE5801@sirena.org.uk> References: <1589800165-3271-1-git-send-email-dillon.minfei@gmail.com> <1589800165-3271-4-git-send-email-dillon.minfei@gmail.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="HeFlAV5LIbMFYYuh" Content-Disposition: inline In-Reply-To: <1589800165-3271-4-git-send-email-dillon.minfei@gmail.com> X-Cookie: C for yourself. User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --HeFlAV5LIbMFYYuh Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Mon, May 18, 2020 at 07:09:20PM +0800, dillon.minfei@gmail.com wrote: > 2, use stm32 spi's "In full-duplex (BIDIMODE=0 and RXONLY=0)", as tx_buf is > null, we must add dummy data sent out before read data. > so, add stm32f4_spi_tx_dummy() to handle this situation. There are flags SPI_CONTROLLER_MUST_TX and SPI_CONTROLLER_MUST_RX flags that the driver can set if it needs to, no need to open code this in the driver. --HeFlAV5LIbMFYYuh Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAl7HuUEACgkQJNaLcl1U h9DV4Qf/SihsJbdjpA046b8/NxOUN0XzKoBRryG9nf4DC4x3Fpb0tscXdk2/FeTd JceAquzFzEEQ49acoXxDA2UQXUMtmlEiGfbWhNHS0Jwo9JVU3XPHLG5d+nX+sudU L+O+LPQB61KcC2OQniMIjgApMjvyj2ePQY0lfjl1jnAb3PLHvlpaUt5Mjp8P0iVB N2skbxjLqD/nDEDYXV+S0Jp689oOuNDJ/zeNk3ds99vhHEc55yvZxvZB8OcWNuop AJ94iVaqJX+b7qak3V7Ts6Hb6GgkNvr/78bWpjGK5eB+a00Ia0l8yP9svyYdczOK GS605iD0geP72ehzZUhOjifzaJ7rgg== =XMsa -----END PGP SIGNATURE----- --HeFlAV5LIbMFYYuh--