1 files changed, 25 insertions, 29 deletions

diff --git a/arch/arm/kernel/hw_breakpoint.c b/arch/arm/kernel/hw_breakpoint.c
index 56ed9a62013b..c9f3f0467570 100644
--- a/arch/arm/kernel/hw_breakpoint.c
+++ b/arch/arm/kernel/hw_breakpoint.c
@@ -219,23 +219,6 @@ static int get_num_brps(void)
         return brps;
 }
 
-int hw_breakpoint_slots(int type)
-{
-        /*
-         * We can be called early, so don't rely on
-         * our static variables being initialised.
-         */
-        switch (type) {
-        case TYPE_INST:
-                return get_num_brps();
-        case TYPE_DATA:
-                return get_num_wrps();
-        default:
-                pr_warning("unknown slot type: %d\n", type);
-                return 0;
-        }
-}
-
 /*
  * In order to access the breakpoint/watchpoint control registers,
  * we must be running in debug monitor mode. Unfortunately, we can
@@ -256,8 +239,12 @@ static int enable_monitor_mode(void)
                 goto out;
         }
 
+        /* If monitor mode is already enabled, just return. */
+        if (dscr & ARM_DSCR_MDBGEN)
+                goto out;
+
         /* Write to the corresponding DSCR. */
-        switch (debug_arch) {
+        switch (get_debug_arch()) {
         case ARM_DEBUG_ARCH_V6:
         case ARM_DEBUG_ARCH_V6_1:
                 ARM_DBG_WRITE(c1, 0, (dscr | ARM_DSCR_MDBGEN));
@@ -272,15 +259,30 @@ static int enable_monitor_mode(void)
 
         /* Check that the write made it through. */
         ARM_DBG_READ(c1, 0, dscr);
-        if (WARN_ONCE(!(dscr & ARM_DSCR_MDBGEN),
-                                "failed to enable monitor mode.")) {
+        if (!(dscr & ARM_DSCR_MDBGEN))
                 ret = -EPERM;
-        }
 
 out:
         return ret;
 }
 
+int hw_breakpoint_slots(int type)
+{
+        /*
+         * We can be called early, so don't rely on
+         * our static variables being initialised.
+         */
+        switch (type) {
+        case TYPE_INST:
+                return get_num_brps();
+        case TYPE_DATA:
+                return get_num_wrps();
+        default:
+                pr_warning("unknown slot type: %d\n", type);
+                return 0;
+        }
+}
+
 /*
  * Check if 8-bit byte-address select is available.
  * This clobbers WRP 0.
@@ -294,9 +296,6 @@ static u8 get_max_wp_len(void)
         if (debug_arch < ARM_DEBUG_ARCH_V7_ECP14)
                 goto out;
 
-        if (enable_monitor_mode())
-                goto out;
-
         memset(&ctrl, 0, sizeof(ctrl));
         ctrl.len = ARM_BREAKPOINT_LEN_8;
         ctrl_reg = encode_ctrl_reg(ctrl);
@@ -879,15 +878,13 @@ static struct notifier_block __cpuinitdata dbg_reset_nb = {
 
 static int __init arch_hw_breakpoint_init(void)
 {
-        int ret = 0;
         u32 dscr;
 
         debug_arch = get_debug_arch();
 
         if (debug_arch > ARM_DEBUG_ARCH_V7_ECP14) {
                 pr_info("debug architecture 0x%x unsupported.\n", debug_arch);
-                ret = -ENODEV;
-                goto out;
+                return 0;
         }
 
         /* Determine how many BRPs/WRPs are available. */
@@ -928,8 +925,7 @@ static int __init arch_hw_breakpoint_init(void)
 
         /* Register hotplug notifier. */
         register_cpu_notifier(&dbg_reset_nb);
-out:
-        return ret;
+        return 0;
 }
 arch_initcall(arch_hw_breakpoint_init);