[9610] wlbt: fix force_disable_mxlogger modparam

Disabling mxlogger using 'force_disable_mxlogger' modparam
is now effective also at system boot-time.

Change-Id: Iccef147570a05b2b92c70c15c7c4a92c067a3ba1
SCSC-Bug-Id: SSB-42080
Signed-off-by: Cristian Marussi <c.marussi@samsung.com>

diff --git a/drivers/misc/samsung/scsc/mxlogger.c b/drivers/misc/samsung/scsc/mxlogger.c
index ba6390324d4d77c578569bfcbfcbabc9f6e8dcfa..5b8f5b5499a6a77dca1c92a2f949503673bb22db 100644 (file)
--- a/drivers/misc/samsung/scsc/mxlogger.c
+++ b/drivers/misc/samsung/scsc/mxlogger.c
@@ -25,6 +25,16 @@
 
 static bool mxlogger_forced_disabled = true;
 
+static void update_fake_observer(void)
+{
+       SCSC_TAG_INFO(MXMAN, "MXLOGGER will now be %sABLED.\n",
+                       mxlogger_forced_disabled ? "DIS" : "EN");
+       if (mxlogger_forced_disabled)
+               mxlogger_register_global_observer("FAKE_OBSERVER");
+       else
+               mxlogger_unregister_global_observer("FAKE_OBSERVER");
+}
+
 static int force_disable_mxlogger_set_param_cb(const char *val,
                                               const struct kernel_param *kp)
 {
@@ -35,15 +45,8 @@ static int force_disable_mxlogger_set_param_cb(const char *val,
 
        if (mxlogger_forced_disabled ^ nval) {
                mxlogger_forced_disabled = nval;
-
-               SCSC_TAG_INFO(MXMAN, "MXLOGGER will now be %sABLED.\n",
-                             mxlogger_forced_disabled ? "FORCIBLY DIS" : "RE-EN");
-               if (mxlogger_forced_disabled)
-                       mxlogger_register_global_observer("FAKE_OBSERVER");
-               else
-                       mxlogger_unregister_global_observer("FAKE_OBSERVER");
+               update_fake_observer();
        }
-
        return 0;
 }
 
@@ -580,6 +583,12 @@ int mxlogger_init(struct scsc_mx *mx, struct mxlogger *mxlogger, uint32_t mem_sz
                return -ENOMEM;
        }
 
+       /**
+        * Update observers status considering
+        * current value of mxlogger_forced_disabled
+        */
+       update_fake_observer();
+
        mutex_lock(&global_lock);
        mxlogger->observers = active_global_observers;
        if (mxlogger->observers)
@@ -641,13 +650,30 @@ int mxlogger_start(struct mxlogger *mxlogger)
                return -ENOMEM;
        }
 
-       /* Enabling before switching direction to avoid msg lost */
-       mxlogger_enable(mxlogger, true);
-
-       if (mxlogger->observers == 0)
+       /**
+        * MXLOGGER on FW-side is at this point starting up too during
+        * WLBT chip boot and it cannot make any assumption till about
+        * the current number of observers and direction set: so, during
+        * MXLOGGER FW-side initialization, ZERO observers were registered.
+        *
+        * As a consequence on chip-boot FW-MXLOGGER defaults to:
+        *  - direction DRAM
+        *  - all rings disabled (ingressing messages discarded)
+        */
+       if (!mxlogger->observers) {
+               /* Enabling BEFORE communicating direction DRAM
+                * to avoid losing messages on rings.
+                */
+               mxlogger_enable(mxlogger, true);
                mxlogger_to_shared_dram(mxlogger);
-       else
+       } else {
                mxlogger_to_host(mxlogger);
+               /* Enabling AFTER communicating direction HOST
+                * to avoid wrongly spilling messages into the
+                * rings early at start (like at boot).
+                */
+               mxlogger_enable(mxlogger, true);
+       }
 
        SCSC_TAG_INFO(MXMAN, "MXLOGGER Configured.\n");
        mutex_unlock(&mxlogger->lock);