[PATCH 2/2] mmc: sdhci: Defer probe if regulator_get fails
From: Philip Rakity <hidden>
Date: 2012-10-23 13:22:16
Also in:
linux-mmc, linux-tegra, lkml
On 23 Oct 2012, at 09:19, Pavan Kunapuli [off-list ref] wrote:
quoted hunk ↗ jump to hunk
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 <redacted> --- 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.
quoted hunk ↗ jump to hunk
} 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 at vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html