--- zzzz-none-000/linux-2.6.39.4/arch/x86/kernel/cpu/amd.c	2011-08-03 19:43:28.000000000 +0000
+++ puma6-arm-6490-729/linux-2.6.39.4/arch/x86/kernel/cpu/amd.c	2021-11-10 13:23:10.000000000 +0000
@@ -612,11 +612,8 @@
 	}
 #endif
 
-	/*
-	 * Family 0x12 and above processors have APIC timer
-	 * running in deep C states.
-	 */
-	if (c->x86 > 0x11)
+	/* As a rule processors have APIC timer running in deep C states */
+	if (c->x86 > 0xf && !cpu_has_amd_erratum(amd_erratum_400))
 		set_cpu_cap(c, X86_FEATURE_ARAT);
 
 	/*
@@ -632,13 +629,10 @@
 		 * Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=33012
 		 */
 		u64 mask;
-		int err;
 
-		err = rdmsrl_safe(MSR_AMD64_MCx_MASK(4), &mask);
-		if (err == 0) {
-			mask |= (1 << 10);
-			checking_wrmsrl(MSR_AMD64_MCx_MASK(4), mask);
-		}
+		rdmsrl(MSR_AMD64_MCx_MASK(4), mask);
+		mask |= (1 << 10);
+		wrmsrl(MSR_AMD64_MCx_MASK(4), mask);
 	}
 }