Re: [PATCH 1/1] efi: rtc: Enable SET/GET WAKEUP services as optional

Alexandre Belloni
2023-01-02T22:22:04Z

On 02/01/2023 11:47:11+0100, Ard Biesheuvel wrote:
> On Tue, 27 Dec 2022 at 05:09, Shanker Donthineni <sdonthineni@nvidia.com> wrote:
> >
> > The current implementation of rtc-efi is expecting all the 4
> > time services GET{SET}_TIME{WAKEUP} must be supported by UEFI
> > firmware. As per the EFI_RT_PROPERTIES_TABLE, the platform
> > specific implementations can choose to enable selective time
> > services based on the RTC device capabilities.
> >
> > This patch does the following changes to provide GET/SET RTC
> > services on platforms that do not support the WAKEUP feature.
> >
> > 1) Relax time services cap check when creating a platform device.
> > 2) Clear RTC_FEATURE_ALARM bit in the absence of WAKEUP services.
> > 3) Conditional alarm entries in '/proc/driver/rtc'.
> >
> > Signed-off-by: Shanker Donthineni <sdonthineni@nvidia.com>
>
> Queued as a fix in efi/urgent, thanks.

This rather seems like an rtc heavy patch and the subject line is
misleading. This should be rtc: efi:
Also, I'm pretty sure this doesn't qualify as an urgent fix.

>
>
> > ---
> > drivers/rtc/rtc-efi.c | 48 ++++++++++++++++++++++++-------------------
> > include/linux/efi.h | 3 ++-
> > 2 files changed, 29 insertions(+), 22 deletions(-)
> >
> > diff --git a/drivers/rtc/rtc-efi.c b/drivers/rtc/rtc-efi.c
> > index e991cccdb6e9c..1e8bc6cc1e12d 100644
> > --- a/drivers/rtc/rtc-efi.c
> > +++ b/drivers/rtc/rtc-efi.c
> > @@ -188,9 +188,10 @@ static int efi_set_time(struct device *dev, struct rtc_time *tm)
> >
> > static int efi_procfs(struct device *dev, struct seq_file *seq)
> > {
> > - efi_time_t eft, alm;
> > - efi_time_cap_t cap;
> > - efi_bool_t enabled, pending;
> > + efi_time_t eft, alm;
> > + efi_time_cap_t cap;
> > + efi_bool_t enabled, pending;
> > + struct rtc_device *rtc = dev_get_drvdata(dev);
> >
> > memset(&eft, 0, sizeof(eft));
> > memset(&alm, 0, sizeof(alm));
> > @@ -213,23 +214,25 @@ static int efi_procfs(struct device *dev, struct seq_file *seq)
> > /* XXX fixme: convert to string? */
> > seq_printf(seq, "Timezone\t: %u\n", eft.timezone);
> >
> > - seq_printf(seq,
> > - "Alarm Time\t: %u:%u:%u.%09u\n"
> > - "Alarm Date\t: %u-%u-%u\n"
> > - "Alarm Daylight\t: %u\n"
> > - "Enabled\t\t: %s\n"
> > - "Pending\t\t: %s\n",
> > - alm.hour, alm.minute, alm.second, alm.nanosecond,
> > - alm.year, alm.month, alm.day,
> > - alm.daylight,
> > - enabled == 1 ? "yes" : "no",
> > - pending == 1 ? "yes" : "no");
> > -
> > - if (eft.timezone == EFI_UNSPECIFIED_TIMEZONE)
> > - seq_puts(seq, "Timezone\t: unspecified\n");
> > - else
> > - /* XXX fixme: convert to string? */
> > - seq_printf(seq, "Timezone\t: %u\n", alm.timezone);
> > + if (test_bit(RTC_FEATURE_ALARM, rtc->features)) {
> > + seq_printf(seq,
> > + "Alarm Time\t: %u:%u:%u.%09u\n"
> > + "Alarm Date\t: %u-%u-%u\n"
> > + "Alarm Daylight\t: %u\n"
> > + "Enabled\t\t: %s\n"
> > + "Pending\t\t: %s\n",
> > + alm.hour, alm.minute, alm.second, alm.nanosecond,
> > + alm.year, alm.month, alm.day,
> > + alm.daylight,
> > + enabled == 1 ? "yes" : "no",
> > + pending == 1 ? "yes" : "no");
> > +
> > + if (eft.timezone == EFI_UNSPECIFIED_TIMEZONE)
> > + seq_puts(seq, "Timezone\t: unspecified\n");
> > + else
> > + /* XXX fixme: convert to string? */
> > + seq_printf(seq, "Timezone\t: %u\n", alm.timezone);
> > + }
> >
> > /*
> > * now prints the capabilities
> > @@ -269,7 +272,10 @@ static int __init efi_rtc_probe(struct platform_device *dev)
> >
> > rtc->ops = &efi_rtc_ops;
> > clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->features);
> > - set_bit(RTC_FEATURE_ALARM_WAKEUP_ONLY, rtc->features);
> > + if (efi_rt_services_supported(EFI_RT_SUPPORTED_WAKEUP_SERVICES))
> > + set_bit(RTC_FEATURE_ALARM_WAKEUP_ONLY, rtc->features);
> > + else
> > + clear_bit(RTC_FEATURE_ALARM, rtc->features);
> >
> > device_init_wakeup(&dev->dev, true);
> >
> > diff --git a/include/linux/efi.h b/include/linux/efi.h
> > index 4b27519143f56..98598bd1d2fa5 100644
> > --- a/include/linux/efi.h
> > +++ b/include/linux/efi.h
> > @@ -668,7 +668,8 @@ extern struct efi {
> >
> > #define EFI_RT_SUPPORTED_ALL 0x3fff
> >
> > -#define EFI_RT_SUPPORTED_TIME_SERVICES 0x000f
> > +#define EFI_RT_SUPPORTED_TIME_SERVICES 0x0003
> > +#define EFI_RT_SUPPORTED_WAKEUP_SERVICES 0x000c
> > #define EFI_RT_SUPPORTED_VARIABLE_SERVICES 0x0070
> >
> > extern struct mm_struct efi_mm;
> > --
> > 2.25.1
> >

--
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering