rtc: cmos: Revert "rtc: Fix the AltCentury value on AMD/Hygon platform"

mainline inclusion
from mainline-v5.5-rc6
commit f01f4ffd
category: bugfix
bugzilla: NA
CVE: NA
---------------------------

There are multiple reports of this patch breaking RTC time setting for AMD
platforms.

This reverts commit 7ad295d5.

Cc: Jinke Fan <fanjinke@hygon.cn>
Link: https://lore.kernel.org/r/CABXGCsMLob0DC25JS8wwAYydnDoHBSoMh2_YLPfqm3TTvDE-Zw@mail.gmail.com
Fixes: 7ad295d5 ("rtc: Fix the AltCentury value on AMD/Hygon platform")
Link: https://lore.kernel.org/r/20200104043110.707810-1-alexandre.belloni@bootlin.comSigned-off-by: NAlexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: NHanjun Guo <guohanjun@huawei.com>
Reviewed-by: NXie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

drivers/rtc/rtc-mc146818-lib.c

@@ -171,20 +171,7 @@ int mc146818_set_time(struct rtc_time *time)
 	save_control = CMOS_READ(RTC_CONTROL);
 	CMOS_WRITE((save_control|RTC_SET), RTC_CONTROL);
 	save_freq_select = CMOS_READ(RTC_FREQ_SELECT);
-
-#ifdef CONFIG_X86
-	if ((boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
-	     boot_cpu_data.x86 == 0x17) ||
-	     boot_cpu_data.x86_vendor == X86_VENDOR_HYGON) {
-		CMOS_WRITE((save_freq_select & (~RTC_DIV_RESET2)),
-			RTC_FREQ_SELECT);
-		save_freq_select &= ~RTC_DIV_RESET2;
-	} else
-		CMOS_WRITE((save_freq_select | RTC_DIV_RESET2),
-			RTC_FREQ_SELECT);
-#else
-	CMOS_WRITE((save_freq_select | RTC_DIV_RESET2), RTC_FREQ_SELECT);
-#endif
+	CMOS_WRITE((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT);
 
 #ifdef CONFIG_MACH_DECSTATION
 	CMOS_WRITE(real_yrs, RTC_DEC_YEAR);