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 X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D9884C43610 for ; Sun, 11 Nov 2018 20:35:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A598020871 for ; Sun, 11 Nov 2018 20:35:24 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A598020871 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=decadent.org.uk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731744AbeKLGYx (ORCPT ); Mon, 12 Nov 2018 01:24:53 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:49908 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730193AbeKLFsN (ORCPT ); Mon, 12 Nov 2018 00:48:13 -0500 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1gLvsZ-0000l7-8v; Sun, 11 Nov 2018 19:58:43 +0000 Received: from ben by deadeye with local (Exim 4.91) (envelope-from ) id 1gLvsW-0001iF-2p; Sun, 11 Nov 2018 19:58:40 +0000 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Ulf Hansson" , "Stefan Agner" Date: Sun, 11 Nov 2018 19:49:05 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 241/366] mmc: sdhci-esdhc-imx: allow 1.8V modes without 100/200MHz pinctrl states In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.61-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Stefan Agner commit 92748beac07c471d995fbec642b63572dc01b3dc upstream. If pinctrl nodes for 100/200MHz are missing, the controller should not select any mode which need signal frequencies 100MHz or higher. To prevent such speed modes the driver currently uses the quirk flag SDHCI_QUIRK2_NO_1_8_V. This works nicely for SD cards since 1.8V signaling is required for all faster modes and slower modes use 3.3V signaling only. However, there are eMMC modes which use 1.8V signaling and run below 100MHz, e.g. DDR52 at 1.8V. With using SDHCI_QUIRK2_NO_1_8_V this mode is prevented. When using a fixed 1.8V regulator as vqmmc-supply the stack has no valid mode to use. In this tenuous situation the kernel continuously prints voltage switching errors: mmc1: Switching to 3.3V signalling voltage failed Avoid using SDHCI_QUIRK2_NO_1_8_V and prevent faster modes by altering the SDHCI capability register. With that the stack is able to select 1.8V modes even if no faster pinctrl states are available: # cat /sys/kernel/debug/mmc1/ios ... timing spec: 8 (mmc DDR52) signal voltage: 1 (1.80 V) ... Link: http://lkml.kernel.org/r/20180628081331.13051-1-stefan@agner.ch Signed-off-by: Stefan Agner Fixes: ad93220de7da ("mmc: sdhci-esdhc-imx: change pinctrl state according to uhs mode") Signed-off-by: Ulf Hansson [bwh: Backported to 3.16: - There is no SDHCI_SUPPORT_HS400 flag to clear - Adjust context] Signed-off-by: Ben Hutchings --- --- a/drivers/mmc/host/sdhci-esdhc-imx.c +++ b/drivers/mmc/host/sdhci-esdhc-imx.c @@ -261,6 +261,15 @@ static u32 esdhc_readl_le(struct sdhci_h val = SDHCI_SUPPORT_DDR50 | SDHCI_SUPPORT_SDR104 | SDHCI_SUPPORT_SDR50 | SDHCI_USE_SDR50_TUNING; + + /* + * Do not advertise faster UHS modes if there are no + * pinctrl states for 100MHz/200MHz. + */ + if (IS_ERR_OR_NULL(imx_data->pins_100mhz) || + IS_ERR_OR_NULL(imx_data->pins_200mhz)) + val &= ~(SDHCI_SUPPORT_SDR50 | SDHCI_SUPPORT_DDR50 + | SDHCI_SUPPORT_SDR104); } } @@ -1108,15 +1117,6 @@ static int sdhci_esdhc_imx_probe(struct ESDHC_PINCTRL_STATE_100MHZ); imx_data->pins_200mhz = pinctrl_lookup_state(imx_data->pinctrl, ESDHC_PINCTRL_STATE_200MHZ); - if (IS_ERR(imx_data->pins_100mhz) || - IS_ERR(imx_data->pins_200mhz)) { - dev_warn(mmc_dev(host->mmc), - "could not get ultra high speed state, work on normal mode\n"); - /* fall back to not support uhs by specify no 1.8v quirk */ - host->quirks2 |= SDHCI_QUIRK2_NO_1_8_V; - } - } else { - host->quirks2 |= SDHCI_QUIRK2_NO_1_8_V; } err = sdhci_add_host(host);