If there's no ACPI DSM for voltage switch, it will just cause a lot of debug info down the line, we only need one at startup. Signed-off-by: Anisse Astier <anisse@xxxxxxxxx> --- drivers/mmc/host/sdhci-pci-core.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/drivers/mmc/host/sdhci-pci-core.c b/drivers/mmc/host/sdhci-pci-core.c index f2c1fb339d66..95fdbb883c7e 100644 --- a/drivers/mmc/host/sdhci-pci-core.c +++ b/drivers/mmc/host/sdhci-pci-core.c @@ -723,6 +723,7 @@ static const struct dmi_system_id board_no_1_8v[] = { static void byt_probe_slot(struct sdhci_pci_slot *slot) { struct mmc_host_ops *ops = &slot->host->mmc_host_ops; + struct intel_host *intel_host = sdhci_pci_priv(slot); byt_read_dsm(slot); @@ -733,6 +734,16 @@ static void byt_probe_slot(struct sdhci_pci_slot *slot) mmc_hostname(slot->host->mmc)); slot->host->quirks2 |= SDHCI_QUIRK2_NO_1_8_V; } + /* Check if we have the appropriate voltage switch DSM methods */ + if (!(intel_host->dsm_fns & (1 << INTEL_DSM_V18_SWITCH)) && + !(intel_host->dsm_fns & (1 << INTEL_DSM_V33_SWITCH))) { + /* No voltage switching supported at all, there's no + * point in installing the callback: return. + */ + pr_debug("%s: No voltage switching ACPI DSM helper\n", + mmc_hostname(slot->host->mmc)); + return; + } ops->start_signal_voltage_switch = intel_start_signal_voltage_switch; } -- 2.17.2