From patchwork Thu Jun 30 02:01:01 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chaotian Jing X-Patchwork-Id: 9206457 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 4703D6075F for ; Thu, 30 Jun 2016 02:02:48 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 378E4284AA for ; Thu, 30 Jun 2016 02:02:48 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 2C4D3285FB; Thu, 30 Jun 2016 02:02:48 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E0D1B285F9 for ; Thu, 30 Jun 2016 02:02:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752659AbcF3CCO (ORCPT ); Wed, 29 Jun 2016 22:02:14 -0400 Received: from mailgw02.mediatek.com ([210.61.82.184]:40461 "EHLO mailgw02.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1751840AbcF3CB0 (ORCPT ); Wed, 29 Jun 2016 22:01:26 -0400 Received: from mtkhts07.mediatek.inc [(172.21.101.69)] by mailgw02.mediatek.com (envelope-from ) (mhqrelay.mediatek.com ESMTP with TLS) with ESMTP id 2075940870; Thu, 30 Jun 2016 10:01:22 +0800 Received: from localhost.localdomain (10.17.3.153) by mtkhts07.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 14.3.266.1; Thu, 30 Jun 2016 10:01:21 +0800 From: Chaotian Jing To: Ulf Hansson CC: Matthias Brugger , Chaotian Jing , Nicolas Boichat , Douglas Anderson , Geert Uytterhoeven , , , , , , Sascha Hauer , Daniel Kurtz , Wei-Ning Huang Subject: [PATCH 4/4] mmc: mediatek: perfer to use rise edge latching Date: Thu, 30 Jun 2016 10:01:01 +0800 Message-ID: <1467252061-3791-5-git-send-email-chaotian.jing@mediatek.com> X-Mailer: git-send-email 1.8.1.1.dirty In-Reply-To: <1467252061-3791-1-git-send-email-chaotian.jing@mediatek.com> References: <1467252061-3791-1-git-send-email-chaotian.jing@mediatek.com> MIME-Version: 1.0 X-MTK: N Sender: linux-mmc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP in our host design, rise edge latching is more stable than fall edge latching. so that if rise edge has enough margin, no need scan fall edge. Signed-off-by: Chaotian Jing --- drivers/mmc/host/mtk-sd.c | 23 ++++++++++++++--------- 1 file changed, 14 insertions(+), 9 deletions(-) diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c index 91277b9..84e9afc 100644 --- a/drivers/mmc/host/mtk-sd.c +++ b/drivers/mmc/host/mtk-sd.c @@ -1328,7 +1328,7 @@ static int msdc_tune_response(struct mmc_host *mmc, u32 opcode) { struct msdc_host *host = mmc_priv(mmc); u32 rise_delay = 0, fall_delay = 0; - struct msdc_delay_phase final_rise_delay, final_fall_delay; + struct msdc_delay_phase final_rise_delay, final_fall_delay = { 0,}; u8 final_delay, final_maxlen; int cmd_err; int i; @@ -1341,6 +1341,11 @@ static int msdc_tune_response(struct mmc_host *mmc, u32 opcode) if (!cmd_err) rise_delay |= (1 << i); } + final_rise_delay = get_best_delay(host, rise_delay); + /* if rising edge has enough margin, then do not scan falling edge */ + if (final_rise_delay.maxlen >= 10 || + (final_rise_delay.start == 0 && final_rise_delay.maxlen >= 4)) + goto skip_fall; sdr_set_bits(host->base + MSDC_IOCON, MSDC_IOCON_RSPL); for (i = 0; i < PAD_DELAY_MAX; i++) { @@ -1350,10 +1355,9 @@ static int msdc_tune_response(struct mmc_host *mmc, u32 opcode) if (!cmd_err) fall_delay |= (1 << i); } - - final_rise_delay = get_best_delay(host, rise_delay); final_fall_delay = get_best_delay(host, fall_delay); +skip_fall: final_maxlen = max(final_rise_delay.maxlen, final_fall_delay.maxlen); if (final_maxlen == final_rise_delay.maxlen) { sdr_clr_bits(host->base + MSDC_IOCON, MSDC_IOCON_RSPL); @@ -1374,7 +1378,7 @@ static int msdc_tune_data(struct mmc_host *mmc, u32 opcode) { struct msdc_host *host = mmc_priv(mmc); u32 rise_delay = 0, fall_delay = 0; - struct msdc_delay_phase final_rise_delay, final_fall_delay; + struct msdc_delay_phase final_rise_delay, final_fall_delay = { 0,}; u8 final_delay, final_maxlen; int i, ret; @@ -1387,6 +1391,11 @@ static int msdc_tune_data(struct mmc_host *mmc, u32 opcode) if (!ret) rise_delay |= (1 << i); } + final_rise_delay = get_best_delay(host, rise_delay); + /* if rising edge has enough margin, then do not scan falling edge */ + if (final_rise_delay.maxlen >= 10 || + (final_rise_delay.start == 0 && final_rise_delay.maxlen >= 4)) + goto skip_fall; sdr_set_bits(host->base + MSDC_IOCON, MSDC_IOCON_DSPL); sdr_set_bits(host->base + MSDC_IOCON, MSDC_IOCON_W_DSPL); @@ -1397,14 +1406,10 @@ static int msdc_tune_data(struct mmc_host *mmc, u32 opcode) if (!ret) fall_delay |= (1 << i); } - - final_rise_delay = get_best_delay(host, rise_delay); final_fall_delay = get_best_delay(host, fall_delay); +skip_fall: final_maxlen = max(final_rise_delay.maxlen, final_fall_delay.maxlen); - /* Rising edge is more stable, prefer to use it */ - if (final_rise_delay.maxlen >= 10) - final_maxlen = final_rise_delay.maxlen; if (final_maxlen == final_rise_delay.maxlen) { sdr_clr_bits(host->base + MSDC_IOCON, MSDC_IOCON_DSPL); sdr_clr_bits(host->base + MSDC_IOCON, MSDC_IOCON_W_DSPL);