From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexandre Courbot Subject: Possible regression with commit 52221610d Date: Tue, 4 Nov 2014 12:05:04 +0900 Message-ID: <54584260.8030602@nvidia.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from hqemgate15.nvidia.com ([216.228.121.64]:12084 "EHLO hqemgate15.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751218AbaKDDF2 (ORCPT ); Mon, 3 Nov 2014 22:05:28 -0500 Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Tim Kryger , Sachin Kamat , Ulf Hansson Cc: linux-mmc@vger.kernel.org, "linux-kernel@vger.kernel.org" , Alexandre Courbot Hi guys, On the NVIDIA shield (tegra114-roth) platform, I have noticed that MMC stopped working completely on recent kernels. MMC devices will not show up and the message "mmc1: Controller never released inhibit bit(s)." shows up repeatedly in the console. After bisecting I tracked commit 52221610dd84dc3e9196554f0292ca9e8ab3541d ("mmc: sdhci: Improve external VDD regulator support") as the one that introduced this issue, which seems somehow surprising to me since it has been around for a while and nobody else complained about this AFAICT. The following diff solves the issue for me, however I don't know whether it also reverts the intended purpose of the initial patch: diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index ada1a3ea3a87..615701bb8ea3 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -1235,13 +1235,6 @@ static void sdhci_set_power(struct sdhci_host *host, unsigned char mode, struct mmc_host *mmc = host->mmc; u8 pwr = 0; - if (!IS_ERR(mmc->supply.vmmc)) { - spin_unlock_irq(&host->lock); - mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, vdd); - spin_lock_irq(&host->lock); - return; - } - if (mode != MMC_POWER_OFF) { switch (1 << vdd) { case MMC_VDD_165_195: @@ -1300,6 +1293,12 @@ static void sdhci_set_power(struct sdhci_host *host, unsigned char mode, if (host->quirks & SDHCI_QUIRK_DELAY_AFTER_POWER) mdelay(10); } + + if (!IS_ERR(mmc->supply.vmmc)) { + spin_unlock_irq(&host->lock); + mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, vdd); + spin_lock_irq(&host->lock); + } } Does this look like the right approach? If not, would you have any suggestion as to how to solve this problem? Thanks, Alex.