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=-9.0 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=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 51CA8C432BE for ; Fri, 23 Jul 2021 17:48:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 37F4160F02 for ; Fri, 23 Jul 2021 17:48:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231481AbhGWRH0 (ORCPT ); Fri, 23 Jul 2021 13:07:26 -0400 Received: from mail.kernel.org ([198.145.29.99]:49674 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230098AbhGWRHZ (ORCPT ); Fri, 23 Jul 2021 13:07:25 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 38CD660EFD; Fri, 23 Jul 2021 17:47:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1627062478; bh=wAsX2Nk+nTgle1kPTUQiq6x5TqfTNwwyAmYsvPzwE04=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=BDEQH6Bsm11H6Hc13n07saNw1FLi/zd00LorhzeUQdBEmBaLMk74maF3DPOsHYQNV r+5qo+rs18oU7qUOkCCRq0uY6UvHzqsu+Os/qyhLaYPKC4jwOf0rm4oChUYhDgOwCA WwWhMllOzR5tHwCJbAUbz2kVxkVi3b0zxGwCMYlblqUqQWIgE5waU/wH7CFgPky1l5 07FVh0zdqgS4DowpOI24zZUGErIwHnnIunyY6DHIWXFwVHa1JiQgLRVKGXnb7lVBJb k2DuZOGAKPgrYLdKoAiCcD1pht4ac+xaEmqnjUQqSB3MJ0fnSbrPg0xvCFpfD34xfq 5wunHoDJtxXUg== Date: Fri, 23 Jul 2021 18:47:51 +0100 From: Mark Brown To: Jonathan Cameron Cc: Puranjay Mohan , Michael.Hennerich@analog.com, alexandru.ardelean@analog.com, jic23@kernel.org, devicetree@vger.kernel.org, linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org, lars@metafoo.de, Dragos.Bogdan@analog.com, Darius.Berghe@analog.com Subject: Re: [PATCH v2 2/2] iio: accel: Add driver support for ADXL355 Message-ID: <20210723174751.GL5221@sirena.org.uk> References: <20210723184404.0000001d@Huawei.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="rfwNdt5cNUUjB/69" Content-Disposition: inline In-Reply-To: <20210723184404.0000001d@Huawei.com> X-Cookie: Integrity has no need for rules. User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --rfwNdt5cNUUjB/69 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Jul 23, 2021 at 06:44:04PM +0100, Jonathan Cameron wrote: > Mark Brown wrote: > > > @Mark. This has come up a few times recently. Are we now safe to as= sume > > > that regmap will always copy data when used with SPI and hence we no > > > longer need to ensure DMA safe buffers? =20 > > Only for single register I/O, I'd not assume that for things like raw > > I/O. > Thanks for the confirmation. So in this driver that means we > need DMA safe buffers for the regmap_bulk_ calls. Easiest approach > is probably to use a __cacheline_aligned buffer at the end of the > iio_priv() structure. Yeah, it might be fine depending on the bus/format type but it's not something you can generally assume. --rfwNdt5cNUUjB/69 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAmD7AMcACgkQJNaLcl1U h9CP+Qf+Lsc5GFkzeUzJpgvTvqmz/f+mVquFladiTHzq4Vd4lCSrD+l12g2lHQHQ bOgOkoGRi0M/NOCwetKglIQNwyUY8WtGY+I8GNpZL53wN//EjBVF29EyM6/huRxt W+tzv2euWk9Tzq6wKj9P8G7Sa0/kIune3KaxtXA8bmEheJ0OszZBLV3qkY3PYgTF 8GWsGQCGkysrve98sTfQcjWyFsPNFgKhMsBQ6SPYYebK8xtFy9qIezumGkXuWQBw k0PFc9Lwz+X/ownmafloKIzZCmHkbpL87h+SBI6HS7BN6kLWFe1aVzuGDaqJy9HN e64jWE5y4GtlufUNHTpbWH7cfXLeMg== =PJ6s -----END PGP SIGNATURE----- --rfwNdt5cNUUjB/69--