From: Shanker Donthineni sdonthineni@nvidia.com
commit 101ca8d05913b7d1e6e8b9dd792193d4082fff86 upstream.
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'.
Cc: stable@vger.kernel.org # v6.0+ Signed-off-by: Shanker Donthineni sdonthineni@nvidia.com Link: https://lore.kernel.org/r/20230102230630.192911-1-sdonthineni@nvidia.com Signed-off-by: Alexandre Belloni alexandre.belloni@bootlin.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/rtc/rtc-efi.c | 48 +++++++++++++++++++++++++++--------------------- include/linux/efi.h | 3 ++- 2 files changed, 29 insertions(+), 22 deletions(-)
--- a/drivers/rtc/rtc-efi.c +++ b/drivers/rtc/rtc-efi.c @@ -188,9 +188,10 @@ static int efi_set_time(struct device *d
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 /* 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 p
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);
return devm_rtc_register_device(rtc); } --- 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;