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| author | Alexander Graf <agraf@suse.de> | 2016-06-05 11:35:56 +0200 |
|---|---|---|
| committer | Alexandre Belloni <alexandre.belloni@free-electrons.com> | 2016-06-06 17:07:33 +0200 |
| commit | 7368c69c033ff29e8e766f481748113c7adc1d1b (patch) | |
| tree | 4ff05dc68c6c84fc66b02854d9ac12ea6ccd852c /drivers/rtc | |
| parent | 06776c89214a14735fed5519340e2cea88b5b91f (diff) | |
| download | linux-stable-7368c69c033ff29e8e766f481748113c7adc1d1b.tar.gz linux-stable-7368c69c033ff29e8e766f481748113c7adc1d1b.tar.bz2 linux-stable-7368c69c033ff29e8e766f481748113c7adc1d1b.zip | |
rtc: efi: Fail probing if RTC reads don't work
While the EFI spec mandates an RTC, not every implementation actually adheres
to that rule (or can adhere to it - some systems just don't have an RTC).
For those, we really don't want to probe the EFI RTC driver at all, because if
we do we'd get a non-functional driver that does nothing useful but only spills
our kernel log with warnings.
Signed-off-by: Alexander Graf <agraf@suse.de>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Diffstat (limited to 'drivers/rtc')
| -rw-r--r-- | drivers/rtc/rtc-efi.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-efi.c b/drivers/rtc/rtc-efi.c index 96d38609d803..0130afd7fe88 100644 --- a/drivers/rtc/rtc-efi.c +++ b/drivers/rtc/rtc-efi.c @@ -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); |