Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934523AbcJFIeE (ORCPT ); Thu, 6 Oct 2016 04:34:04 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:47024 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752512AbcJFIeA (ORCPT ); Thu, 6 Oct 2016 04:34:00 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jon Hunter , Adrian Hunter , Ulf Hansson Subject: [PATCH 4.7 022/141] mmc: tegra: Only advertise UHS modes if IO regulator is present Date: Thu, 6 Oct 2016 10:27:38 +0200 Message-Id: <20161006074449.550629188@linuxfoundation.org> X-Mailer: git-send-email 2.10.0 In-Reply-To: <20161006074448.608056610@linuxfoundation.org> References: <20161006074448.608056610@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4532 Lines: 108 4.7-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jon Hunter commit 4f6aa3264af4d44caaa649dd3ff1fe98f5817251 upstream. To support UHS modes for Tegra an external regulator must be present to adjust the IO voltage accordingly. Even if the regulator is not present but the host supports the UHS modes and the device supports the UHS modes, then we will attempt to switch to a high-speed mode. Without an external regulator, Tegra will fail to switch to the high-speed mode. It has been found that with some SD cards, that once it has been switch to operate at a high-speed mode, all subsequent commands issues to the card will fail and so it will not be possible to switch back to a non high-speed mode and so the SD card initialisation will fail. The SDHCI core does not require that the host have an external regulator when switching to UHS modes and therefore, the Tegra SDHCI host controller should only advertise the UHS modes as being supported if the regulator for the IO voltage is present. Fortunately, Tegra has a vendor specific register which can be used to control which modes are advertised via the SDHCI_CAPABILITIES register. Hence, if there is no IO voltage regulator available for the Tegra SDHCI host, then don't advertise the UHS modes. Note that if the regulator is not available, we also don't advertise that the SDHCI is compatible with v3.0 of the SDHCI specification because this will read the SDHCI_CAPABILITIES_1 register which will enable other UHS modes. This fixes commit 7ad2ed1dfcbe ("mmc: tegra: enable UHS-I modes") which enables UHS mode without checking if the board can support them. Fixes: 7ad2ed1dfcbe ("mmc: tegra: enable UHS-I modes") Signed-off-by: Jon Hunter Acked-by: Adrian Hunter Signed-off-by: Ulf Hansson Signed-off-by: Greg Kroah-Hartman --- drivers/mmc/host/sdhci-tegra.c | 49 ++++++++++++++++++++++++----------------- 1 file changed, 29 insertions(+), 20 deletions(-) --- a/drivers/mmc/host/sdhci-tegra.c +++ b/drivers/mmc/host/sdhci-tegra.c @@ -148,28 +148,37 @@ static void tegra_sdhci_reset(struct sdh return; misc_ctrl = sdhci_readl(host, SDHCI_TEGRA_VENDOR_MISC_CTRL); - /* Erratum: Enable SDHCI spec v3.00 support */ - if (soc_data->nvquirks & NVQUIRK_ENABLE_SDHCI_SPEC_300) - misc_ctrl |= SDHCI_MISC_CTRL_ENABLE_SDHCI_SPEC_300; - /* Advertise UHS modes as supported by host */ - if (soc_data->nvquirks & NVQUIRK_ENABLE_SDR50) - misc_ctrl |= SDHCI_MISC_CTRL_ENABLE_SDR50; - else - misc_ctrl &= ~SDHCI_MISC_CTRL_ENABLE_SDR50; - if (soc_data->nvquirks & NVQUIRK_ENABLE_DDR50) - misc_ctrl |= SDHCI_MISC_CTRL_ENABLE_DDR50; - else - misc_ctrl &= ~SDHCI_MISC_CTRL_ENABLE_DDR50; - if (soc_data->nvquirks & NVQUIRK_ENABLE_SDR104) - misc_ctrl |= SDHCI_MISC_CTRL_ENABLE_SDR104; - else - misc_ctrl &= ~SDHCI_MISC_CTRL_ENABLE_SDR104; - sdhci_writel(host, misc_ctrl, SDHCI_TEGRA_VENDOR_MISC_CTRL); - clk_ctrl = sdhci_readl(host, SDHCI_TEGRA_VENDOR_CLOCK_CTRL); + + misc_ctrl &= ~(SDHCI_MISC_CTRL_ENABLE_SDHCI_SPEC_300 | + SDHCI_MISC_CTRL_ENABLE_SDR50 | + SDHCI_MISC_CTRL_ENABLE_DDR50 | + SDHCI_MISC_CTRL_ENABLE_SDR104); + clk_ctrl &= ~SDHCI_CLOCK_CTRL_SPI_MODE_CLKEN_OVERRIDE; - if (soc_data->nvquirks & SDHCI_MISC_CTRL_ENABLE_SDR50) - clk_ctrl |= SDHCI_CLOCK_CTRL_SDR50_TUNING_OVERRIDE; + + /* + * If the board does not define a regulator for the SDHCI + * IO voltage, then don't advertise support for UHS modes + * even if the device supports it because the IO voltage + * cannot be configured. + */ + if (!IS_ERR(host->mmc->supply.vqmmc)) { + /* Erratum: Enable SDHCI spec v3.00 support */ + if (soc_data->nvquirks & NVQUIRK_ENABLE_SDHCI_SPEC_300) + misc_ctrl |= SDHCI_MISC_CTRL_ENABLE_SDHCI_SPEC_300; + /* Advertise UHS modes as supported by host */ + if (soc_data->nvquirks & NVQUIRK_ENABLE_SDR50) + misc_ctrl |= SDHCI_MISC_CTRL_ENABLE_SDR50; + if (soc_data->nvquirks & NVQUIRK_ENABLE_DDR50) + misc_ctrl |= SDHCI_MISC_CTRL_ENABLE_DDR50; + if (soc_data->nvquirks & NVQUIRK_ENABLE_SDR104) + misc_ctrl |= SDHCI_MISC_CTRL_ENABLE_SDR104; + if (soc_data->nvquirks & SDHCI_MISC_CTRL_ENABLE_SDR50) + clk_ctrl |= SDHCI_CLOCK_CTRL_SDR50_TUNING_OVERRIDE; + } + + sdhci_writel(host, misc_ctrl, SDHCI_TEGRA_VENDOR_MISC_CTRL); sdhci_writel(host, clk_ctrl, SDHCI_TEGRA_VENDOR_CLOCK_CTRL); if (soc_data->nvquirks & NVQUIRK_HAS_PADCALIB)