[PATCH V1] mmc: sdhci: Fix potential null pointer access while accessing vqmmc

From: Veerabhadrarao Badiganti
Date: Thu Jul 09 2020 - 09:14:02 EST


Don't access vqmmc regulator handler, if it's already invalidated.

Fixes: f870b6d480d3 (mmc: sdhci: Allow platform controlled voltage switching)
Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Veerabhadrarao Badiganti <vbadigan@xxxxxxxxxxxxxx>
---
drivers/mmc/host/sdhci.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index e6275c2202b0..d3b62fc5c661 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -4383,11 +4383,6 @@ int sdhci_setup_host(struct sdhci_host *host)
if (!IS_ERR(mmc->supply.vqmmc)) {
if (enable_vqmmc) {
ret = regulator_enable(mmc->supply.vqmmc);
- if (ret) {
- pr_warn("%s: Failed to enable vqmmc regulator: %d\n",
- mmc_hostname(mmc), ret);
- mmc->supply.vqmmc = ERR_PTR(-EINVAL);
- }
host->sdhci_core_to_disable_vqmmc = !ret;
}

@@ -4402,6 +4397,13 @@ int sdhci_setup_host(struct sdhci_host *host)
if (!regulator_is_supported_voltage(mmc->supply.vqmmc, 2700000,
3600000))
host->flags &= ~SDHCI_SIGNALING_330;
+
+ if (ret) {
+ pr_warn("%s: Failed to enable vqmmc regulator: %d\n",
+ mmc_hostname(mmc), ret);
+ mmc->supply.vqmmc = ERR_PTR(-EINVAL);
+ }
+
}

if (host->quirks2 & SDHCI_QUIRK2_NO_1_8_V) {
--
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