File ppc64_cpu-Clean-up-sysfs-smt-control-error-handling.patch of Package powerpc-utils.32342

From 916a239f518e96c77c35a58db7f1dcc00e5fb5f0 Mon Sep 17 00:00:00 2001
From: Michal Suchanek <msuchanek@suse.de>
Date: Fri, 9 Feb 2024 13:12:33 +0100
Subject: [PATCH] ppc64_cpu: Clean up sysfs smt/control error handling

When the kernel does not support the sysfs intercface do not report and
arror, fall back to the old method silently.

Suggested-by: Nathan Lynch<nathanl@linux.ibm.com>
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
---
It has been suggested to also not try the old iterface in case of
unknown error because it's unlikely to work but that would needlessly
complicate the code.
---
 src/ppc64_cpu.c | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/src/ppc64_cpu.c b/src/ppc64_cpu.c
index c318928..759ceff 100644
--- a/src/ppc64_cpu.c
+++ b/src/ppc64_cpu.c
@@ -368,10 +368,20 @@ static int is_dscr_capable(void)
 static int set_smt_control(int smt_state)
 {
 	if (set_attribute(SYS_SMT_CONTROL, "%d", smt_state)) {
-		/* Silently ignore kernel not supporting this feature */
-		if (errno != ENODEV)
-			perror(SYS_SMT_CONTROL);
-		return -1;
+		switch (errno) {
+			case ENOENT:
+			/*
+			 * The kernel does not have the interface.
+			 * Try the old method.
+			 */
+				return -1;
+			case ENODEV:
+			/* Setting SMT state not supported on the system. */
+				return 0;
+			default:
+				perror(SYS_SMT_CONTROL);
+				return -1;
+		}
 	}
 	return 0;
 }
-- 
2.43.0