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 lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (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 8A5F1C6FD18 for ; Wed, 29 Mar 2023 20:17:19 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4PmyWx6L54z3fRy for ; Thu, 30 Mar 2023 07:17:17 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=P5U564E9; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=kernel.org (client-ip=139.178.84.217; helo=dfw.source.kernel.org; envelope-from=conor@kernel.org; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=P5U564E9; dkim-atps=neutral Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4PmyVw4b48z3cLs for ; Thu, 30 Mar 2023 07:16:24 +1100 (AEDT) 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 0ABA761DEE; Wed, 29 Mar 2023 20:16:21 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BAEB3C433D2; Wed, 29 Mar 2023 20:16:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1680120980; bh=GQ/BnFe9Q8YTrp9m/Oja+3F+vgOfqDylgmr9jLCscRs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=P5U564E993rrDoh13ZYMd/KR6rZkNdIdAbkwy4AMMyuaZ2UnsINcIgdKLJGQbZT1R zUAUZnpQCzF0TlpEQXZmdxZiDMl23kcqvk8c8s2jxRsSMekf7FDxCi9gR1oX2Da8hi aag+2sE6WG2TyEHXWa4HzYKbVaDqQKSeZs+SUyrFuRdRhxxhHTm9szdrtMzu032YBF pnLWBxLnUyF1yY234OeM4zx5JvWcQ8+nbW2h2BxGSx1xSG/83/MuR/yVSH7mdi1xg2 0jWbdD9E6OkE4eGUQzkyJv6rP5bdfMAHDI8/GyVgtoddbv/rL55kO33CXzMD08MgAw CkixnBQ6Xb9Yw== Date: Wed, 29 Mar 2023 21:16:10 +0100 From: Conor Dooley To: Arnd Bergmann Subject: Re: [PATCH 09/21] riscv: dma-mapping: skip invalidation before bidirectional DMA Message-ID: <764e8d2f-ed98-49dc-8fdb-112d59359148@spud> References: <20230327121317.4081816-1-arnd@kernel.org> <20230327121317.4081816-10-arnd@kernel.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="2LJh6dsRB07q9YeN" Content-Disposition: inline In-Reply-To: <20230327121317.4081816-10-arnd@kernel.org> X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Rich Felker , linux-sh@vger.kernel.org, Catalin Marinas , Linus Walleij , John Paul Adrian Glaubitz , linux-mips@vger.kernel.org, Max Filippov , Conor Dooley , Guo Ren , linux-csky@vger.kernel.org, sparclinux@vger.kernel.org, linux-riscv@lists.infradead.org, Will Deacon , Christoph Hellwig , Helge Deller , Russell King , Geert Uytterhoeven , Vineet Gupta , linux-snps-arc@lists.infradead.org, linux-xtensa@linux-xtensa.org, Arnd Bergmann , Brian Cain , Lad Prabhakar , linux-m68k@lists.linux-m68k.org, Paul Walmsley , Stafford Horne , linux-arm-kernel@lists.infradead.org, Neil Armstrong , Michal Simek , Thomas Bogendoerfer , linux-parisc@vger.kernel.org, linux-openrisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, Dinh Nguyen , Palmer Dabbelt , linux-hexagon@vger.kernel.org, linux-oxnas@groups.io, Robin Murphy , "David S. Miller" Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" --2LJh6dsRB07q9YeN Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Mar 27, 2023 at 02:13:05PM +0200, Arnd Bergmann wrote: > From: Arnd Bergmann >=20 > For a DMA_BIDIRECTIONAL transfer, the caches have to be cleaned > first to let the device see data written by the CPU, and invalidated > after the transfer to let the CPU see data written by the device. >=20 > riscv also invalidates the caches before the transfer, which does > not appear to serve any purpose. Rationale makes sense to me.. Reviewed-by: Conor Dooley Thanks for working on all of this Arnd! --2LJh6dsRB07q9YeN Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQRh246EGq/8RLhDjO14tDGHoIJi0gUCZCScigAKCRB4tDGHoIJi 0jHpAP47kMhf2uxHoGKhD+jHsEYnFgTHptLnAfIJV6N+QeFoOAD/YxG6hd8qhesW 6Tw9EqBEW/4auX2CLsbK7xE8fP5A9wg= =os1C -----END PGP SIGNATURE----- --2LJh6dsRB07q9YeN--