From: Jaehoon Chung <jh80.chung@samsung.com>
To: Pavan Kunapuli <pkunapuli@nvidia.com>
Cc: swarren@wwwdotorg.org, linux@arm.linux.org.uk, cjb@laptop.org,
linux-kernel@vger.kernel.org, linux-mmc@vger.kernel.org
Subject: Re: [PATCH 2/2] mmc: sdhci: Defer probe if regulator_get fails
Date: Tue, 23 Oct 2012 19:10:49 +0900 [thread overview]
Message-ID: <50866D29.1040709@samsung.com> (raw)
In-Reply-To: <1350976709-19248-3-git-send-email-pkunapuli@nvidia.com>
I didn't understand why defer the probe?
I think that some board can't control vqmmc or vmmc.
Best Regards,
Jaehoon Chung
On 10/23/2012 04:18 PM, 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 <pkunapuli@nvidia.com>
> ---
> 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;
> }
> 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;
> }
>
>
next prev parent reply other threads:[~2012-10-23 10:10 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-23 7:18 [PATCH 0/2] mmc: sdhci: Defer probe if regulators are not registered Pavan Kunapuli
2012-10-23 7:18 ` [PATCH 1/2] ARM: dt: tegra: Add sdhci regulators Pavan Kunapuli
2012-10-23 16:21 ` Stephen Warren
2012-10-23 7:18 ` [PATCH 2/2] mmc: sdhci: Defer probe if regulator_get fails Pavan Kunapuli
2012-10-23 10:10 ` Jaehoon Chung [this message]
2012-10-23 10:17 ` Pavan Kunapuli
2012-10-23 16:23 ` Stephen Warren
-- strict thread matches above, loose matches on Subject: below --
2012-10-23 7:18 [PATCH 0/2] mmc: sdhci: Defer probe if regulators are not registered Pavan Kunapuli
2012-10-23 7:19 ` [PATCH 2/2] mmc: sdhci: Defer probe if regulator_get fails Pavan Kunapuli
2012-10-23 7:57 ` Lucas Stach
2012-10-23 8:16 ` Pavan Kunapuli
2012-10-23 16:29 ` Stephen Warren
2012-10-23 17:07 ` Mark Brown
[not found] ` <1350976740-19284-3-git-send-email-pkunapuli-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
2012-10-23 13:21 ` Philip Rakity
[not found] ` <4F1DF342-A2C4-434A-B878-A11374089E6E-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
2012-10-23 13:36 ` Russell King - ARM Linux
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