If vmmc or vqmmc regulators are controlled by an I2C device, the request for the regulator is likely to fail because the I2C bus has not been probed yet. The sdhci then incorrectly assumes that the user never wanted to use a regulator anyway and continues without ever enabling or configuring the required regulator.
To solve this, when a required voltage regulator returns EPROBE_DEFER, signalling that the regulator exists but is not available yet, forward this error to the probe method instead of simply assuming that the user never wanted to use a regulator anyway. Tested on a custom board that has an I2C regulator for one of the sdhcis and no regulators at all for the other. This patch enables such a system to work correctly. v2: Changed "%d" into "%ld" for PTR_ERR value. --- drivers/mmc/host/sdhci.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index 34aef81..de601f5 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -2972,6 +2972,8 @@ int sdhci_add_host(struct sdhci_host *host) host->vqmmc = regulator_get_optional(mmc_dev(mmc), "vqmmc"); if (IS_ERR_OR_NULL(host->vqmmc)) { if (PTR_ERR(host->vqmmc) < 0) { + if (PTR_ERR(host->vqmmc) == -EPROBE_DEFER) + return -EPROBE_DEFER; pr_info("%s: no vqmmc regulator found\n", mmc_hostname(mmc)); host->vqmmc = NULL; @@ -3048,8 +3050,10 @@ int sdhci_add_host(struct sdhci_host *host) host->vmmc = regulator_get_optional(mmc_dev(mmc), "vmmc"); if (IS_ERR_OR_NULL(host->vmmc)) { if (PTR_ERR(host->vmmc) < 0) { - pr_info("%s: no vmmc regulator found\n", - mmc_hostname(mmc)); + if (PTR_ERR(host->vmmc) == -EPROBE_DEFER) + return -EPROBE_DEFER; + pr_info("%s: no vmmc regulator found (%ld)\n", + mmc_hostname(mmc), PTR_ERR(host->vmmc)); host->vmmc = NULL; } } -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/