Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757142Ab2JWNWQ (ORCPT ); Tue, 23 Oct 2012 09:22:16 -0400 Received: from hqemgate03.nvidia.com ([216.228.121.140]:19747 "EHLO hqemgate03.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756959Ab2JWNWO convert rfc822-to-8bit (ORCPT ); Tue, 23 Oct 2012 09:22:14 -0400 X-PGP-Universal: processed; by hqnvupgp07.nvidia.com on Tue, 23 Oct 2012 06:10:05 -0700 From: Philip Rakity To: Pavan Kunapuli CC: "swarren@wwwdotorg.org" , "linux@arm.linux.org.uk" , "cjb@laptop.org" , "linux-tegra@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , "linux-mmc@vger.kernel.org" Date: Tue, 23 Oct 2012 15:21:58 +0200 Subject: Re: [PATCH 2/2] mmc: sdhci: Defer probe if regulator_get fails Thread-Topic: [PATCH 2/2] mmc: sdhci: Defer probe if regulator_get fails Thread-Index: Ac2xIV+9hU4xejnCTaCP36bCKSYrgQ== Message-ID: <4F1DF342-A2C4-434A-B878-A11374089E6E@nvidia.com> References: <1350976740-19284-1-git-send-email-pkunapuli@nvidia.com> <1350976740-19284-3-git-send-email-pkunapuli@nvidia.com> In-Reply-To: <1350976740-19284-3-git-send-email-pkunapuli@nvidia.com> Accept-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US MIME-Version: 1.0 Content-Language: en-US Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2923 Lines: 86 On 23 Oct 2012, at 09:19, Pavan Kunapuli wrote: > vmmc and vqmmc regulators control the voltage to > the host and device. Defer the probe if either of > them is not registered. > > Signed-off-by: Pavan Kunapuli > --- > drivers/mmc/host/sdhci.c | 25 ++++++++++++++++++++++--- > 1 files changed, 22 insertions(+), 3 deletions(-) > > diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c > index 7922adb..925c403 100644 > --- a/drivers/mmc/host/sdhci.c > +++ b/drivers/mmc/host/sdhci.c > @@ -2844,11 +2844,17 @@ int sdhci_add_host(struct sdhci_host *host) > !(host->mmc->caps & MMC_CAP_NONREMOVABLE)) > mmc->caps |= MMC_CAP_NEEDS_POLL; > > - /* If vqmmc regulator and no 1.8V signalling, then there's no UHS */ > + /* > + * If vqmmc regulator and no 1.8V signalling, then there's no UHS. > + * vqmmc regulator should be present. If it's not present, > + * assume the regulator driver registration is not yet done and > + * defer the probe. > + */ > host->vqmmc = regulator_get(mmc_dev(mmc), "vqmmc"); > if (IS_ERR(host->vqmmc)) { > - pr_info("%s: no vqmmc regulator found\n", mmc_hostname(mmc)); > + pr_err("%s: no vqmmc regulator found\n", mmc_hostname(mmc)); > host->vqmmc = NULL; > + return -EPROBE_DEFER; Some systems exist where vmmc regulator exists and vqmmc regulator does not. The vmmc regular is fixed at 3.3v. Deferring the probe will cause issues. > } > else if (regulator_is_supported_voltage(host->vqmmc, 1800000, 1800000)) > regulator_enable(host->vqmmc); > @@ -2903,10 +2909,17 @@ int sdhci_add_host(struct sdhci_host *host) > > ocr_avail = 0; > > + /* > + * vmmc regulator should be present. If it's not present, > + * assume the regulator driver registration is not yet done > + * and defer the probe. > + */ > host->vmmc = regulator_get(mmc_dev(mmc), "vmmc"); > if (IS_ERR(host->vmmc)) { > - pr_info("%s: no vmmc regulator found\n", mmc_hostname(mmc)); > + pr_err("%s: no vmmc regulator found\n", mmc_hostname(mmc)); > host->vmmc = NULL; > + ret = -EPROBE_DEFER; > + goto vmmc_err; > } else > regulator_enable(host->vmmc); > > @@ -3121,7 +3134,13 @@ reset: > untasklet: > tasklet_kill(&host->card_tasklet); > tasklet_kill(&host->finish_tasklet); > +vmmc_err: > + if (host->vqmmc) { > + if (regulator_is_enabled(host->vqmmc)) > + regulator_disable(host->vqmmc); > > + regulator_put(host->vqmmc); > + } > return ret; > } > > -- > 1.7.1.1 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-mmc" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/