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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 02371C00140 for ; Wed, 10 Aug 2022 12:39:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Content-Type: List-Subscribe:List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id: In-Reply-To:MIME-Version:References:Message-ID:Subject:Cc:To:From:Date: Reply-To:Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date :Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=Fm9niVI2EMveMF4+j65g9cpqvxa/r2WvV73PlGakHIg=; b=l6fGq6k+522X5omLns9R5KWPEj ModyZ9q4clhKu6RQEpvXiWTsmqUJZOQKYBOU572bwcC9eTQkb/DUORNCrXagUjA+2L5XCutM95y2O area5Frc11SaTMlKRHYYlPUoVfLzrG3Sg6YGbkC1MbyO9CwbfM+CZdFMh7bBaUlgYXsb87IeTjLMe 0/U/3jIt1X6F+Bic1p/SK1mN9NO5P1B7l6wEhJDiD7gQMdIrVs3wRHBN0C4NEHgyTmXEYfj4pg0Mi UAyuTMRjgV78YX6yr6KpFz1Qdk+ZfUc02V7H1z1a4aIkVBMQADRG3YlFwAMDQndUxIm8qAeMRsCgL L7xjnvfg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1oLkyF-00Bo8k-HY; Wed, 10 Aug 2022 12:37:59 +0000 Received: from dfw.source.kernel.org ([2604:1380:4641:c500::1]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1oLkyB-00Bo79-NP; Wed, 10 Aug 2022 12:37:57 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 2A12161363; Wed, 10 Aug 2022 12:37:54 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2C7B5C433D6; Wed, 10 Aug 2022 12:37:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1660135073; bh=ROHaIZk75ZgJisF7nTMLDJS9o0AxLi1V/y+T67/KwWQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Qg7V+bjI7lf3dzSN62yYr9g4pSgwDtQDJWcjI3dRgZRvMIoOD/bbKegaOJMO2MzWN SE+A3aKfjpe80HoF1s2lo5xVS6gIkpmA1DpXIUnW2aHmkkpf3RJ/y8dJotPeQecNET e5qc36Vnk3SFh2ixHl5EoVsn2FhJ3CmaaVXyK9sh5fVsJqfdHGFcit844ItnozYVb6 CGZ4Ma5LOKbVbJtmpUwe4+JSb49OOdw677rfq2XdN3V5GeorsO5RJZw/LAVbThEAK4 woyx4cJp5ybMTB/NJtCaI8FBAu4HmfiRtObEhNrpbt1GgSGGFejKux81LEpIDva+n8 xCEk6z1CseItQ== Date: Wed, 10 Aug 2022 13:37:48 +0100 From: Mark Brown To: Neil Armstrong Cc: linux-spi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-amlogic@lists.infradead.org, linux-kernel@vger.kernel.org, Da Xue Subject: Re: [PATCH] spi: meson-spicc: save pow2 datarate between messages Message-ID: References: <20220809152019.461741-1-narmstrong@baylibre.com> <39c2f53b-8f53-ceb1-ae0c-81e5e53d01aa@baylibre.com> MIME-Version: 1.0 In-Reply-To: <39c2f53b-8f53-ceb1-ae0c-81e5e53d01aa@baylibre.com> X-Cookie: First pull up, then pull down. X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220810_053755_824429_A09FA8AD X-CRM114-Status: GOOD ( 19.16 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: multipart/mixed; boundary="===============4907300656042031095==" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org --===============4907300656042031095== Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="2hd26sDiWQtv5ujx" Content-Disposition: inline --2hd26sDiWQtv5ujx Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Wed, Aug 10, 2022 at 11:17:14AM +0200, Neil Armstrong wrote: > On 09/08/2022 17:27, Mark Brown wrote: > > On Tue, Aug 09, 2022 at 05:20:19PM +0200, Neil Armstrong wrote: > > When you say the value set by the clock framework does that mean that > > the clock driver is adjusting hardware inside the SPI controller IP > > block which is then getting reset by the SPI driver without the SPI > > driver knowing about it? That seems like a bad idea as you're finding > > here. > The SPI driver is explicitely triggering a reset at the end of each message > to get back to a clean HW state, but it does reset the content of the "legacy" > registers containing the power of 2 divider value, the new registers configuring > the new clock divider path (only on newer SoCs) doesn't get cleared. Sure, but that doesn't really address the concern - is this something that the clk driver programmed or is this the driver forgetting to restore a register that it programmed itself? The commit message sounds like the former which is a much bigger problem. --2hd26sDiWQtv5ujx Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAmLzppwACgkQJNaLcl1U h9CP8Qf/cMQYM72jnQkNExfj6dskX5IIOlwCnAVUEnsbYrFpv3QL6BNLxgKx4eqx cjDy+gszIhOd4rr7/ayE4siN6fjOo/hWNIuydrrCsRWKrjvKTUInWB16AnVv5NrK JAjl3RZ9vrkKp2UcN/dsaU11B5Xce59ko2nuniDhKYZhubO9F2uYxOPiBLvufQyU Q20TDeHIgYaClQvbbnVnIBpjkeOYaZxhkpAjZmw/Btip07mzspkcC4ASnTbTKs2j cCeDY+xkSNPqT+Pie+GxbV0bOeAjLdUOwP7QoXIsrP4BJRzuoHk/aXWC8GzXo13a 3baxwuQr/bFzHeoJRT+a3zrpms9mLA== =yOBS -----END PGP SIGNATURE----- --2hd26sDiWQtv5ujx-- --===============4907300656042031095== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel --===============4907300656042031095==--