be2net: Provide an alternate way to read pf_num for BEx chips
[cascardo/linux.git] / drivers / rtc / rtc-efi.c
index 96d3860..0130afd 100644 (file)
@@ -259,6 +259,12 @@ static const struct rtc_class_ops efi_rtc_ops = {
 static int __init efi_rtc_probe(struct platform_device *dev)
 {
        struct rtc_device *rtc;
+       efi_time_t eft;
+       efi_time_cap_t cap;
+
+       /* First check if the RTC is usable */
+       if (efi.get_time(&eft, &cap) != EFI_SUCCESS)
+               return -ENODEV;
 
        rtc = devm_rtc_device_register(&dev->dev, "rtc-efi", &efi_rtc_ops,
                                        THIS_MODULE);