Re: [PATCH for-4.22 1/5] x86/time: use RTC century byte when available

[Jan Beulich <jbeulich@suse.com>]

On 13.05.2026 10:49, Roger Pau Monné wrote:
> On Tue, May 12, 2026 at 04:58:43PM +0200, Jan Beulich wrote:
>> @@ -1280,6 +1281,8 @@ static bool __get_cmos_time(struct rtc_t
>>      rtc->day  = CMOS_READ(RTC_DAY_OF_MONTH);
>>      rtc->mon  = CMOS_READ(RTC_MONTH);
>>      rtc->year = CMOS_READ(RTC_YEAR);
>> +    if ( acpi_gbl_FADT.century && acpi_gbl_FADT.century < 0x80 )
>> +        century = CMOS_READ(acpi_gbl_FADT.century);
>>      
>>      if ( RTC_ALWAYS_BCD || !(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) )
>>      {
>> @@ -1293,7 +1296,12 @@ static bool __get_cmos_time(struct rtc_t
>>  
>>      spin_unlock_irqrestore(&rtc_lock, flags);
>>  
>> -    if ( (rtc->year += 1900) < 1970 )
>> +    if ( century )
>> +    {
>> +        BCD_TO_BIN(century);
> 
> Don't you need to move the BCD_TO_BIN() translation with the rest, so
> it's not done unconditionally?

No, the century field is always BCD.

Jan