[PATCH 4.9 03/28] x86/MCE: Remove min interval polling limitation

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Dewet Thibaut <thibaut.dewet@xxxxxxxxx>

commit fbdb328c6bae0a7c78d75734a738b66b86dffc96 upstream.

commit b3b7c4795c ("x86/MCE: Serialize sysfs changes") introduced a min
interval limitation when setting the check interval for polled MCEs.
However, the logic is that 0 disables polling for corrected MCEs, see
Documentation/x86/x86_64/machinecheck. The limitation prevents disabling.

Remove this limitation and allow the value 0 to disable polling again.

Fixes: b3b7c4795c ("x86/MCE: Serialize sysfs changes")
Signed-off-by: Dewet Thibaut <thibaut.dewet@xxxxxxxxx>
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@xxxxxxxxx>
[ Massage commit message. ]
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Tony Luck <tony.luck@xxxxxxxxx>
Cc: linux-edac <linux-edac@xxxxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/20180716084927.24869-1-alexander.sverdlin@xxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 arch/x86/kernel/cpu/mcheck/mce.c |    3 ---
 1 file changed, 3 deletions(-)

--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -2397,9 +2397,6 @@ static ssize_t store_int_with_restart(st
 	if (check_interval == old_check_interval)
 		return ret;
 
-	if (check_interval < 1)
-		check_interval = 1;
-
 	mutex_lock(&mce_sysfs_mutex);
 	mce_restart();
 	mutex_unlock(&mce_sysfs_mutex);