[lunar:linux-kvm][PATCH] Revert "UBUNTU: SAUCE: [kvm] tsc: make no_timer_check default to 1"

[Dimitri John Ledkov]

This reverts commit 4ecbc83125d8bab884d6f5790498f910f1cb8e84.

This patch probably did nothing since introduction. Paravirtualized
platforms Hyper-V, VMWare and KVM in their cpu init functions set
no_timer_check = 1, thus setting no_timer_check by default to 1 is
redundant.

Please drop this patch in a rebase.

This patch was dropped in jammy:linux-aws, but was present in earlier
editions of the aws kernel. I am not sure if this patch was
intentionally dropped there, as I don't see anything similar done on
x86 Xen virtualization. Maybe these checks are now desired on AWS
since it is effectively becoming bare-metal.

Signed-off-by: Dimitri John Ledkov <dimitri.ledkov at canonical.com>
---
 Documentation/admin-guide/kernel-parameters.txt |  3 +--
 arch/x86/kernel/apic/io_apic.c                  | 14 ++++----------
 2 files changed, 5 insertions(+), 12 deletions(-)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index af7c3bf3e0..d82ca5185c 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -3736,8 +3736,7 @@
 			disable unhandled interrupt sources.
 
 	no_timer_check	[X86,APIC] Disables the code which tests for
-			broken timer IRQ sources. For AWS, this is defaulted
-			to disabled, can be re-enabled using no_timer_check=0.
+			broken timer IRQ sources.
 
 	noisapnp	[ISAPNP] Disables ISA PnP code.
 
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 0172706b05..a868b76cd3 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -1574,20 +1574,14 @@ void __init setup_ioapic_ids_from_mpc(void)
 }
 #endif
 
-int no_timer_check __initdata = 1;
+int no_timer_check __initdata;
 
 static int __init notimercheck(char *s)
 {
-	int ret = 0;
-
-	if (s)
-		ret = kstrtoint(s, 0, &no_timer_check);
-	else
-		no_timer_check = 1;
-
-	return ret;
+	no_timer_check = 1;
+	return 1;
 }
-early_param("no_timer_check", notimercheck);
+__setup("no_timer_check", notimercheck);
 
 static void __init delay_with_tsc(void)
 {
-- 
2.34.1