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 9D67FC433E0 for ; Tue, 16 Jun 2020 08:26:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6FB9F20767 for ; Tue, 16 Jun 2020 08:26:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592296012; bh=zwfLiiOBJv9xd28/k4MWseO5mRe5jJl7Tlu1GcSaMnQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=U491HM9Tv7xUOeC1/tHiGHT/oV4Lr6j/BRUFn+uTJ4q671SU/syjbVBGWE2wbHsCf 8lmDO+ZW9bujxCS3lf+Ncgwg7xShetIL6IunqePgb3EMWd9upP7bQ/yOysHaH2ZwRf a+sOxhaeyexJ+AxB7q4ETGggzRZttHqmhryY0CtU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727119AbgFPI0w (ORCPT ); Tue, 16 Jun 2020 04:26:52 -0400 Received: from mail.kernel.org ([198.145.29.99]:41636 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726428AbgFPI0v (ORCPT ); Tue, 16 Jun 2020 04:26:51 -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 3265E20739; Tue, 16 Jun 2020 08:26:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592296010; bh=zwfLiiOBJv9xd28/k4MWseO5mRe5jJl7Tlu1GcSaMnQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=w2c2Ybd7/S1rdMjRJx7tdDDHKFcteQHILKII8l5QRlwqqG7w4fzM1hdvsYjm0A4QV SomjjZpuxuPmquQs8zHLOXxAQzPX3D0RE+bgRvFZ0bROzLi133kvtMmZ267oKu32li aZgljVip8ixpLwQtburrAnyZ0HWuJsZDJ5Dc5gsU= Date: Tue, 16 Jun 2020 09:26:48 +0100 From: Mark Brown To: Mark Tomlinson Cc: "linux-spi@vger.kernel.org" , "kdasu.kdev@gmail.com" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH 4/5] spi: bcm-qspi: Make multiple data blocks interrupt-driven Message-ID: <20200616082648.GE4447@sirena.org.uk> References: <20200615040557.2011-1-mark.tomlinson@alliedtelesis.co.nz> <20200615040557.2011-5-mark.tomlinson@alliedtelesis.co.nz> <20200615143233.GW4447@sirena.org.uk> <40bae0160c6e24c3d90d4935eb31cf3de64abc9e.camel@alliedtelesis.co.nz> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="2+IiqX0tbFQDLF7Q" Content-Disposition: inline In-Reply-To: <40bae0160c6e24c3d90d4935eb31cf3de64abc9e.camel@alliedtelesis.co.nz> X-Cookie: Offer may end without notice. User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-spi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org --2+IiqX0tbFQDLF7Q Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Jun 16, 2020 at 03:07:17AM +0000, Mark Tomlinson wrote: > On Mon, 2020-06-15 at 15:32 +0100, Mark Brown wrote: > > Again was this done for a reason and if so do we understand why doing > > this from interrupt context is safe - how long can the interrupts be > > when stuffing the FIFO from interrupt context? > As I'm porting a Broadcom patch, I'm hoping someone else can add > something to this. From the history it appears there was a hard limit If you didn't write this code then it should have at least one signoff =66rom the original source, I can't do anything with this without signoffs - please see Documentation/process/submitting-patches.rst for what this is and why it's important. > (no small chunks), and this was changed to doing it in chunks with > patch 345309fa7c0c92, apparently to improve performance. I believe this > change further improves performance, but as the patch arrived without > any documentation, I'm not certain. Have you tested the impact on performance? --2+IiqX0tbFQDLF7Q Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAl7ogkcACgkQJNaLcl1U h9AeHgf+PeKNVWiTvF5IZERUnylT0z36L9JFKcSvYNtlJFeRKiQEMyF/l1OR2g+U R0TQERq0rcUof2GoqP3L4RgsykGVprSexq8YdIXNe1Zelmjk1H1S9kj4MvxkPKG7 tCX8BRwOz61Lm7elp0aFbsCpYT2JmnpIYlDqiTehjeFJL4VBd11ZUDgv6disFTVA /pkVx2HMscDeBxLRaPBNOZMQy9FElRRV4TNGBjfFxGx0po+5bEk0r+TDPABG4fyG C6QxfPE7venVM5RrNjaljJRh30oBpTawrHo5UiTBefb7og9xBFal6rqpN0pygk79 kFB4dIG9bsuRH3dOtZBqEzYzn1Rdqw== =5Rdi -----END PGP SIGNATURE----- --2+IiqX0tbFQDLF7Q--