From: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Date: Tue, 28 Apr 2026 06:15:40 +0000 (+0530)
Subject: char/nvram: Remove redundant nvram_mutex
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=e8c715f3a7dae43fabae261493a26474fec11863;p=thirdparty%2Flinux.git

char/nvram: Remove redundant nvram_mutex

The global nvram_mutex in drivers/char/nvram.c is redundant and unused,
and this triggers compiler warnings on some configurations.

All platform-specific nvram operations already provide their own internal
synchronization, meaning the wrapper-level mutex does not provide any
additional safety.

Remove the nvram_mutex definition along with all remaining lock/unlock
users across PPC32, x86, and m68k code paths, and rely entirely on the
per-architecture nvram implementations for locking.

Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Tested-by: Tellakula Yeswanth Krishna <yeswanth@linux.ibm.com>
Signed-off-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Tested-by: yeswanth <yeswanth@linux.ibm.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://patch.msgid.link/20260428061540.73668-1-venkat88@linux.ibm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/char/nvram.c b/drivers/char/nvram.c
index 9eff426a92865..e89cc1f1c89ea 100644
--- a/drivers/char/nvram.c
+++ b/drivers/char/nvram.c
@@ -53,7 +53,6 @@
 #include <asm/nvram.h>
 #endif
 
-static DEFINE_MUTEX(nvram_mutex);
 static DEFINE_SPINLOCK(nvram_state_lock);
 static int nvram_open_cnt;	/* #times opened */
 static int nvram_open_mode;	/* special open modes */
@@ -310,11 +309,8 @@ static long nvram_misc_ioctl(struct file *file, unsigned int cmd,
 		break;
 #ifdef CONFIG_PPC32
 	case IOC_NVRAM_SYNC:
-		if (ppc_md.nvram_sync != NULL) {
-			mutex_lock(&nvram_mutex);
+		if (ppc_md.nvram_sync)
 			ppc_md.nvram_sync();
-			mutex_unlock(&nvram_mutex);
-		}
 		ret = 0;
 		break;
 #endif
@@ -324,11 +320,8 @@ static long nvram_misc_ioctl(struct file *file, unsigned int cmd,
 		if (!capable(CAP_SYS_ADMIN))
 			return -EACCES;
 
-		if (arch_nvram_ops.initialize != NULL) {
-			mutex_lock(&nvram_mutex);
+		if (arch_nvram_ops.initialize)
 			ret = arch_nvram_ops.initialize();
-			mutex_unlock(&nvram_mutex);
-		}
 		break;
 	case NVRAM_SETCKS:
 		/* just set checksum, contents unchanged (maybe useful after
@@ -336,11 +329,8 @@ static long nvram_misc_ioctl(struct file *file, unsigned int cmd,
 		if (!capable(CAP_SYS_ADMIN))
 			return -EACCES;
 
-		if (arch_nvram_ops.set_checksum != NULL) {
-			mutex_lock(&nvram_mutex);
+		if (arch_nvram_ops.set_checksum)
 			ret = arch_nvram_ops.set_checksum();
-			mutex_unlock(&nvram_mutex);
-		}
 		break;
 #endif /* CONFIG_X86 || CONFIG_M68K */
 	}