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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 01E1DC43334 for ; Wed, 15 Jun 2022 14:14:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235206AbiFOOOX (ORCPT ); Wed, 15 Jun 2022 10:14:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58912 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1353163AbiFOOOB (ORCPT ); Wed, 15 Jun 2022 10:14:01 -0400 Received: from smtp15.bhosted.nl (smtp15.bhosted.nl [IPv6:2a02:9e0:8000::26]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0E4FC192A5 for ; Wed, 15 Jun 2022 07:13:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=protonic.nl; s=202111; h=content-transfer-encoding:content-type:mime-version:references:in-reply-to: message-id:subject:cc:to:from:date:from; bh=cU63ym4X53fKIlrrBQ5m80vzLbOrXAj7eH4jQuBfPhk=; b=rZ8G/A5cANaBOWo4GVlXVEeUnFjD8b9XrMjf22SJBxIeVipXMcePbxrPNZGtowJ42iuLFOISsjPL2 8QlIRvVq5/HA24GOyYAjbkpFm5DWd9e5LpNBK78kv5HExvj1b8s/QZVD5flsM7DB3EH0pY8Al4ZLwl QKH9HutLgnd4eZD3zxsUi24J9ZEaocpYVt43layo8RTuRzkNQg++Gf5f3Sp9P1DdVcmHSJG4mGk4sa 6UtwMEDSQbeTocZPH8DgbGgBBvcbrOT7FeKhAyd/utPxoNziBT0ZFiiFxKguKhaDfkXQC1xpm80cF/ H69P1PdmSNZMyFW/0bIEHRZDcz0KE/g== X-MSG-ID: 653125ad-ecb5-11ec-ba03-0050569d3a82 Date: Wed, 15 Jun 2022 16:13:56 +0200 From: David Jander To: Marc Kleine-Budde Cc: Mark Brown , linux-spi@vger.kernel.org, Andrew Lunn Subject: Re: [RFC] [PATCH v2 00/11] Optimize spi_sync path Message-ID: <20220615161356.21bf749d@erd992> In-Reply-To: <20220615133113.ylwenlzpkv2na25z@pengutronix.de> References: <20220615124634.3302867-1-david@protonic.nl> <20220615133113.ylwenlzpkv2na25z@pengutronix.de> Organization: Protonic Holland X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org On Wed, 15 Jun 2022 15:31:13 +0200 Marc Kleine-Budde wrote: > On 15.06.2022 14:46:23, David Jander wrote: > > These patches optimize the spi_sync call for the common case that the > > worker thread is idle and the queue is empty. It also opens the > > possibility to potentially further optimize the async path also, since > > it doesn't need to take into account the direct sync path anymore. > > > > As an example for the performance gain, on an i.MX8MM SoC with a SPI CAN > > controller attached (MCP2518FD), the time the interrupt line stays > > active (which corresponds roughly with the time it takes to send 3 > > relatively short consecutive spi_sync messages) is reduced from 98us to > > only 72us by this patch. > > > > A note about message ordering: > > > > This patch series should not change the behavior of message ordering when > > coming from the same context. This means that if a client driver issues > > one or more spi_async() messages immediately followed by a spi_sync() > > message in the same context, it can still rely on these messages being > > sent out in the order they were fired. > > Which git branch to use as the base? Sorry, forgot to mention: spi for-next: git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git This is because it relies on previous patches that have been applied there. -- David Jander