From patchwork Wed Dec 13 23:48:49 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zhoujie Wu X-Patchwork-Id: 10111167 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 C305760327 for ; Wed, 13 Dec 2017 23:48:37 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B5E2E294EB for ; Wed, 13 Dec 2017 23:48:37 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A914429644; Wed, 13 Dec 2017 23:48:37 +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 autolearn=ham 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 31FAD294EB for ; Wed, 13 Dec 2017 23:48:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750819AbdLMXsg (ORCPT ); Wed, 13 Dec 2017 18:48:36 -0500 Received: from mx0a-0016f401.pphosted.com ([67.231.148.174]:44306 "EHLO mx0b-0016f401.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750795AbdLMXsg (ORCPT ); Wed, 13 Dec 2017 18:48:36 -0500 Received: from pps.filterd (m0045849.ppops.net [127.0.0.1]) by mx0a-0016f401.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id vBDNiRUP026519; Wed, 13 Dec 2017 15:48:32 -0800 Received: from sc-exch01.marvell.com ([199.233.58.181]) by mx0a-0016f401.pphosted.com with ESMTP id 2etabp02hg-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-SHA384 bits=256 verify=NOT); Wed, 13 Dec 2017 15:48:32 -0800 Received: from SC-EXCH01.marvell.com (10.93.176.81) by SC-EXCH01.marvell.com (10.93.176.81) with Microsoft SMTP Server (TLS) id 15.0.1210.3; Wed, 13 Dec 2017 15:48:31 -0800 Received: from maili.marvell.com (10.93.176.43) by SC-EXCH01.marvell.com (10.93.176.81) with Microsoft SMTP Server id 15.0.1210.3 via Frontend Transport; Wed, 13 Dec 2017 15:48:31 -0800 Received: from an-git01.marvell.com (unknown [10.80.127.149]) by maili.marvell.com (Postfix) with ESMTP id 9BD413F703F; Wed, 13 Dec 2017 15:48:31 -0800 (PST) From: Zhoujie Wu To: , , CC: , , , , , , , , , , , , Zhoujie Wu Subject: [PATCH v2] mmc: sdhci: wait 5ms after set 1.8V signal enable Date: Wed, 13 Dec 2017 15:48:49 -0800 Message-ID: <1513208929-13578-1-git-send-email-zjwu@marvell.com> X-Mailer: git-send-email 1.9.1 MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2017-12-13_13:, , signatures=0 X-Proofpoint-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=541 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1711220000 definitions=main-1712130322 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 According to SD spec 3.00 3.6.1 signal voltage switch procedure, host should wait 5ms after set 1.8V signal enable bit in Host Control 2 register and check if 1.8V is stable or not. On some cards, found without the delay would see "1.8V regulator output did not became stable" err log. Signed-off-by: Zhoujie Wu --- v2: removed undeliverable cc email address. drivers/mmc/host/sdhci.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index e9290a3..fe5f208 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -1933,6 +1933,9 @@ int sdhci_start_signal_voltage_switch(struct mmc_host *mmc, if (host->ops->voltage_switch) host->ops->voltage_switch(host); + /* Wait for 5ms */ + usleep_range(5000, 5500); + /* 1.8V regulator output should be stable within 5 ms */ ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2); if (ctrl & SDHCI_CTRL_VDD_180)