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[23.128.96.18]) by mx.google.com with ESMTP id u5si9429369ejb.53.2020.06.15.07.38.19; Mon, 15 Jun 2020 07:38:42 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=sRnd9myu; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730610AbgFOOgZ (ORCPT + 99 others); Mon, 15 Jun 2020 10:36:25 -0400 Received: from mail.kernel.org ([198.145.29.99]:55602 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728326AbgFOOgZ (ORCPT ); Mon, 15 Jun 2020 10:36:25 -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 3C5FE206B7; Mon, 15 Jun 2020 14:36:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592231784; bh=ype2UwsEJQA9RCKVIpGpA9vIFkTyIQOQ4sKP1eAXFbM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=sRnd9myuAlE2K1Nj2iURRl7w9qJ8EkYdNdH+K+1/phMf0kpQoAY1Pxp7TJ1JfE1Bv IS0K9Zxia4mxtl4V1nzuqvNO6G2NXNI+bmmTQPTgW5XKEnO5J9uL2LHNVwhcwBS3Ik ag3vadWejMFiNKgNM8XdbJeap+BU3716MyK6XAPQ= Date: Mon, 15 Jun 2020 15:36:22 +0100 From: Mark Brown To: Robin Gong Cc: Vinod Koul , "shawnguo@kernel.org" , "s.hauer@pengutronix.de" , "festevam@gmail.com" , "robin.murphy@arm.com" , "matthias.schiffer@ew.tq-group.com" , "kernel@pengutronix.de" , dl-linux-imx , "linux-spi@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH v1 RFC 1/2] spi: introduce fallback to pio Message-ID: <20200615143622.GX4447@sirena.org.uk> References: <20200611134042.GG4671@sirena.org.uk> <20200612101357.GA5396@sirena.org.uk> <20200612141611.GI5396@sirena.org.uk> <20200615123553.GP4447@sirena.org.uk> <20200615133905.GV4447@sirena.org.uk> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="6yuPXOSZRpyw7iEV" Content-Disposition: inline In-Reply-To: X-Cookie: Offer may end without notice. 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 --6yuPXOSZRpyw7iEV Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Jun 15, 2020 at 02:18:54PM +0000, Robin Gong wrote: > On 2020/06/15 21:39 Mark Brown wrote: > > On Mon, Jun 15, 2020 at 01:35:01PM +0000, Robin Gong wrote: > > > Then how about choosing specific error code for such dma not ready > > > case where nothing went out on the bus neither? > > Yes, that's what I suggested. > Seems not easy to find a suitable error value, how about EBADR which > sounds like no any available dma_async_tx_descriptor got by calling dmaen= gine_prep_slave_sg?=20 > #define EBADR 53 /* Invalid request descriptor */ We could also pass in a flag that could be set separately to the error code to indicate that nothing had happened to the hardware yet. --6yuPXOSZRpyw7iEV Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAl7nh2UACgkQJNaLcl1U h9CGngf9FJjxiiGTABi3SIsOJXFnGblWLqB3vln9SMDIbAPj/yGiDdpERP2vrY1W 7k5dVCoCvMS3H85xHNvGXPWcWiAMdr2kvxYtHSOXafk/x18RNkFypSPrJGNH8aFa bJAFTdhXBNO1Tzkfyv8jEXenmexA8Zvr98tiCjY6y1KzVIxXUS76Z0m610y3t01m tBtsjAkAXoKe7N00fwx6mhZKwOlOmj7xXhETXAWGi7hMipmWTMlBDfijumFNivy0 ZmZdGZkr7H8rmKS664LAce29F1vBAGJ1DDCR7uZPNz0Tv2hT7gOTadOvuionzbvw c1zT5i2KtlUGpSNfABZa0rmrPwY5dg== =DUZv -----END PGP SIGNATURE----- --6yuPXOSZRpyw7iEV--