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 75557C43334 for ; Fri, 15 Jul 2022 14:13:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229846AbiGOONv (ORCPT ); Fri, 15 Jul 2022 10:13:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41736 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235294AbiGOONt (ORCPT ); Fri, 15 Jul 2022 10:13:49 -0400 Received: from esa.microchip.iphmx.com (esa.microchip.iphmx.com [68.232.153.233]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7AF5BB493 for ; Fri, 15 Jul 2022 07:13:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=microchip.com; i=@microchip.com; q=dns/txt; s=mchp; t=1657894427; x=1689430427; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=5s0qRLHgkSjM5AY2vqOMfzZmbKyjDGXVrUPOcHa/fP4=; b=DCBMTHFZhvQhR7KIgaW+lwZ+Mi3DNSWKLzIBlc6c8whodP1dVh12NQi7 Ql+iu6aghIcmfeiXWNlpQGk1MmnyNiXMUywsFqSbcM42cnUwaNMCn1St+ tqzqJJDsRyzXtmSuNF1El5sOEurzqVn9v/3UqN8NkN4boDGzQW9WWc7gV p7J2ATr7fMhyvwBfUDHzzZrG4wucVu1KPTg5nAXifldHp0svUNyEf57CJ byHvQANB0ktPrxuJ5zO5otep+cjH28l9AoTU4ra6bJ7cY4yJv0+ld8HVp PGOjhdfwfFcuZkKekrjAU0gp55wxR65oDchxs0E47eIiqSzxMxq8t6rQ0 w==; X-IronPort-AV: E=Sophos;i="5.92,274,1650956400"; d="scan'208";a="172301575" Received: from unknown (HELO email.microchip.com) ([170.129.1.10]) by esa5.microchip.iphmx.com with ESMTP/TLS/AES256-SHA256; 15 Jul 2022 07:13:46 -0700 Received: from chn-vm-ex03.mchp-main.com (10.10.85.151) by chn-vm-ex01.mchp-main.com (10.10.85.143) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.17; Fri, 15 Jul 2022 07:13:45 -0700 Received: from HNO-LT-M43677A.mchp-main.com (10.10.115.15) by chn-vm-ex03.mchp-main.com (10.10.85.151) with Microsoft SMTP Server id 15.1.2375.17 via Frontend Transport; Fri, 15 Jul 2022 07:13:44 -0700 From: Thomas Kopp To: CC: , , , Subject: Re: [PATCH v3 00/11] Optimize spi_sync path Date: Fri, 15 Jul 2022 16:13:42 +0200 Message-ID: <20220715141342.12330-1-thomas.kopp@microchip.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220621061234.3626638-1-david@protonic.nl> References: <20220621061234.3626638-1-david@protonic.nl> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org Hi David, some numbers after testing your patch on a RPI 5.15.y vs 5.19rc6 and the mcp2518fd: Two Backtoback SPI transfers with 9 byte each went from 78us to 36us! All metrics improved (cs to first clock cyle, last clock cycle to cs, and delay between two transfers). That's a great help for the mcp driver (or any similar SPI device). Thanks for your work on this! -Thomas