From patchwork Thu Apr 17 17:59:27 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Doug Anderson X-Patchwork-Id: 4010111 Return-Path: X-Original-To: patchwork-linux-samsung-soc@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 37D619F2BA for ; Thu, 17 Apr 2014 18:00:59 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 67910201BB for ; Thu, 17 Apr 2014 18:00:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 953F220117 for ; Thu, 17 Apr 2014 18:00:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751256AbaDQSAp (ORCPT ); Thu, 17 Apr 2014 14:00:45 -0400 Received: from mail-pd0-f201.google.com ([209.85.192.201]:56619 "EHLO mail-pd0-f201.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751357AbaDQSAT (ORCPT ); Thu, 17 Apr 2014 14:00:19 -0400 Received: by mail-pd0-f201.google.com with SMTP id x10so92611pdj.4 for ; Thu, 17 Apr 2014 11:00:18 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=nBA1o+FCkG9rZu/WbjV64uQUJuBptfb1XKvBsoBdvRk=; b=Z98+M314BL7hlGD3GNgRlyDyIOrla2cYGiqVlh9raJJV6cjAogEKTc8avflZdJVHMP ba8aEbiNHLDqqPYHDJ9W4Gc24x41xwrVYChMGoXuefd/rRH0PMDa8MxKj1M7IsJoI/z7 6XU92qbm3Drf+xydk4OwHexRlOip3P5m4FC7LYzawzZvSlPa3KI9RHNDugQwvIuTaQ0F QRq0Cei0FlLWNWu1OgbG6KT9lRnmtPROqNYMFjjbpsQJ+XhwCKO5TtTMLVK7vofahODE NsJE2l+SsO5iFnNJ6AjLsIfH7YQ2QKFWtAJ70dmunznY0XZVGOe0w5s+7UCtuY7jmP8D Wo9g== X-Gm-Message-State: ALoCoQmIBPMzU6KHUkeCiO4ZHh9UHgzyDpj7rX0Z0mUSS5AsvEXmsRRgQmtSvHI+aAQubwRmCtVbL8aoimHyCkUGcJL0nFjFiOPzi00lSqEQf5aJm5zahRFZQCU57sEEGWjOHlDSnVYLighFMPaZG+eWEu+xAFSKGBV4q4hR/sMGcfRBDzoG/eG8LeRyb9Qx8Pvnb0Ku3hUgJQCuKO2mJ1akxCEESaKdLQ== X-Received: by 10.66.251.70 with SMTP id zi6mr4229962pac.37.1397757617985; Thu, 17 Apr 2014 11:00:17 -0700 (PDT) Received: from corp2gmr1-1.hot.corp.google.com (corp2gmr1-1.hot.corp.google.com [172.24.189.92]) by gmr-mx.google.com with ESMTPS id y50si136673yhk.4.2014.04.17.11.00.17 for (version=TLSv1.1 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Thu, 17 Apr 2014 11:00:17 -0700 (PDT) Received: from tictac.mtv.corp.google.com (tictac.mtv.corp.google.com [172.22.72.141]) by corp2gmr1-1.hot.corp.google.com (Postfix) with ESMTP id C23F931C2F7; Thu, 17 Apr 2014 11:00:17 -0700 (PDT) Received: by tictac.mtv.corp.google.com (Postfix, from userid 121310) id 77BDF80D95; Thu, 17 Apr 2014 11:00:17 -0700 (PDT) From: Doug Anderson To: Lee Jones , Stephen Warren , Wolfram Sang Cc: abrestic@chromium.org, dgreid@chromium.org, Olof Johansson , Simon Glass , linux-samsung-soc@vger.kernel.org, linux-tegra@vger.kernel.org, Doug Anderson , Samuel Ortiz , linux-kernel@vger.kernel.org Subject: [PATCH 4/7] mfd: cros_ec: spi: Increase cros_ec_spi deadline from 5ms to 100ms Date: Thu, 17 Apr 2014 10:59:27 -0700 Message-Id: <1397757570-19750-5-git-send-email-dianders@chromium.org> X-Mailer: git-send-email 1.9.1.423.g4596e3a In-Reply-To: <1397757570-19750-1-git-send-email-dianders@chromium.org> References: <1397757570-19750-1-git-send-email-dianders@chromium.org> Sender: linux-samsung-soc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-samsung-soc@vger.kernel.org X-Spam-Status: No, score=-7.6 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP We're adding i2c tunneling to the list of things that goes over cros_ec. i2c tunneling can be slooooooow, so increase our deadline to 100ms to account for that. Signed-off-by: Doug Anderson Reviewed-by: Simon Glass --- drivers/mfd/cros_ec_spi.c | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-) diff --git a/drivers/mfd/cros_ec_spi.c b/drivers/mfd/cros_ec_spi.c index 4f863c3..0b8d328 100644 --- a/drivers/mfd/cros_ec_spi.c +++ b/drivers/mfd/cros_ec_spi.c @@ -39,14 +39,22 @@ #define EC_MSG_PREAMBLE_COUNT 32 /* - * We must get a response from the EC in 5ms. This is a very long - * time, but the flash write command can take 2-3ms. The EC command - * processing is currently not very fast (about 500us). We could - * look at speeding this up and making the flash write command a - * 'slow' command, requiring a GET_STATUS wait loop, like flash - * erase. - */ -#define EC_MSG_DEADLINE_MS 5 + * Allow for a long time for the EC to respond. We support i2c + * tunneling and support fairly long messages for the tunnel (249 + * bytes long at the moment). If we're talking to a 100 kHz device + * on the other end and need to transfer ~256 bytes, then we need: + * 10 us/bit * ~10 bits/byte * ~256 bytes = ~25ms + * + * We'll wait 4 times that to handle clock stretching and other + * paranoia. + * + * It's pretty unlikely that we'll really see a 249 byte tunnel in + * anything other than testing. If this was more common we might + * consider having slow commands like this require a GET_STATUS + * wait loop. The 'flash write' command would be another candidate + * for this, clocking in at 2-3ms. + */ +#define EC_MSG_DEADLINE_MS 100 /* * Time between raising the SPI chip select (for the end of a