sysmobts: Enable the PA on start and disable it as first action

The PA will be unconditionally turned. This makes it possible
that in case of a crash, the PA will be turned on and then we
will do the temperature measurement and turn it off again. There
are no known crashes with the sysmobts-mgr right now so the risk
seems to be okay. In case we can't switch off the PA we have no
way to escalate it right now. We have not seen a dead uc either
so the risk is okay as well.

We can't switch the PA back on once we reach the normal level
as the BTS might transmit with full power and we would need more
current than the power supply/rails can carry. So leave the
system off right now.

What is missing is to use the OML router to actually inform
the BSC that something bad has happened at the BTS.

src/osmo-bts-sysmo/misc/sysmobts_mgr.c

@@ -73,7 +73,7 @@ static struct sysmobts_mgr_instance manager = {
 		.thresh_crit	= 100,
 	},
 	.action_warn		= 0,
-	.action_crit		= 0,
+	.action_crit		= TEMP_ACT_PA_OFF,
 	.state			= STATE_NORMAL,
 };
 

src/osmo-bts-sysmo/misc/sysmobts_mgr_2050.c

@@ -247,7 +247,7 @@ int sbts2050_uc_get_status(struct sbts2050_power_status *status)
 /**********************************************************************
  *	Uc Power Switching handling
  *********************************************************************/
-void sbts2050_uc_set_power(int pmaster, int pslave, int ppa)
+int sbts2050_uc_set_power(int pmaster, int pslave, int ppa)
 {
 	struct msgb *msg;
 	const struct ucinfo info = {
@@ -261,7 +261,7 @@ void sbts2050_uc_set_power(int pmaster, int pslave, int ppa)
 
 	if (msg == NULL) {
 		LOGP(DTEMP, LOGL_ERROR, "Error switching off some unit.\n");
-		return;
+		return -1;
 	}
 
 	LOGP(DTEMP, LOGL_DEBUG, "Switch off/on success:\n"
@@ -273,6 +273,7 @@ void sbts2050_uc_set_power(int pmaster, int pslave, int ppa)
 				ppa ? "ON" : "OFF");
 
 	msgb_free(msg);
+	return 0;
 }
 
 /**********************************************************************
@@ -317,6 +318,20 @@ void sbts2050_uc_initialize(void)
 		     "Failed to open the serial interface\n");
 		return;
 	}
+
+	LOGP(DTEMP, LOGL_NOTICE, "Going to enable the PA.\n");
+	sbts2050_uc_set_pa_power(1);
+}
+
+int sbts2050_uc_set_pa_power(int on_off)
+{
+	struct sbts2050_power_status status;
+	if (sbts2050_uc_get_status(&status) != 0) {
+		LOGP(DTEMP, LOGL_ERROR, "Failed to read current power status.\n");
+		return -1;
+	}
+
+	return sbts2050_uc_set_power(status.master_enabled, status.slave_enabled, on_off);
 }
 #else
 void sbts2050_uc_initialize(void)
@@ -338,4 +353,10 @@ int sbts2050_uc_get_status(struct sbts2050_power_status *status)
 	return -1;
 }
 
+int sbts2050_uc_set_pa_power(int on_off)
+{
+	LOGP(DTEMP, LOGL_ERROR, "sysmoBTS2050 compiled without PA support.\n");
+	return -1;
+}
+
 #endif

src/osmo-bts-sysmo/misc/sysmobts_mgr_temp.c

@@ -96,6 +96,26 @@ static void execute_warning_act(struct sysmobts_mgr_instance *manager)
 static void execute_critical_act(struct sysmobts_mgr_instance *manager)
 {
 	LOGP(DTEMP, LOGL_NOTICE, "System has reached critical warning.\n");
+
+	/* switch off the PA */
+	if (manager->action_crit & TEMP_ACT_PA_OFF) {
+		if (!is_sbts2050_master()) {
+			LOGP(DTEMP, LOGL_NOTICE,
+				"PA can only be switched-off on the master\n");
+		} else if (sbts2050_uc_set_pa_power(0) != 0) {
+			LOGP(DTEMP, LOGL_ERROR,
+				"Failed to switch off the PA. Stop BTS?\n");
+		} else {
+			LOGP(DTEMP, LOGL_NOTICE,
+				"Switched off the PA due temperature.\n");
+		}
+		/*
+		 * TODO: remember we switched off things so we could switch
+		 * it back on. But we would need to make sure that the BTS
+		 * will not transmit with full power at that time. This
+		 * requires the control protocol.
+		 */
+	}
 }
 
 static void sysmobts_mgr_temp_handle(struct sysmobts_mgr_instance *manager,

src/osmo-bts-sysmo/misc/sysmobts_mgr_vty.c

@@ -167,9 +167,9 @@ static void write_action(struct vty *vty, const char *name, int actions)
 		(actions & TEMP_ACT_MASTER_OFF) ? "" : "no ", VTY_NEWLINE);
 	vty_out(vty, "  %sslave-off%s",
 		(actions & TEMP_ACT_MASTER_OFF) ? "" : "no ", VTY_NEWLINE);
+#endif
 	vty_out(vty, "  %spa-off%s",
 		(actions & TEMP_ACT_PA_OFF) ? "" : "no ", VTY_NEWLINE);
-#endif
 }
 
 static int config_write_mgr(struct vty *vty)
@@ -239,6 +239,24 @@ CFG_ACTION(warn, "Warning Actions\n", ACT_WARN_NODE, action_warn)
 CFG_ACTION(critical, "Critical Actions\n", ACT_CRIT_NODE, action_crit)
 #undef CFG_ACTION
 
+DEFUN(cfg_action_pa_off, cfg_action_pa_off_cmd,
+	"pa-off",
+	"Switch the Power Amplifier off\n")
+{
+	int *action = vty->index;
+	*action |= TEMP_ACT_PA_OFF;
+	return CMD_SUCCESS;
+}
+
+DEFUN(cfg_no_action_pa_off, cfg_no_action_pa_off_cmd,
+	"no pa-off",
+	NO_STR "Do not switch off the Power Amplifier\n")
+{
+	int *action = vty->index;
+	*action &= ~TEMP_ACT_PA_OFF;
+	return CMD_SUCCESS;
+}
+
 DEFUN(show_mgr, show_mgr_cmd, "show manager",
       SHOW_STR "Display information about the manager")
 {
@@ -303,9 +321,9 @@ static void register_action(int act)
 	install_element(act, &cfg_no_action_master_off_cmd);
 	install_element(act, &cfg_action_slave_off_cmd);
 	install_element(act, &cfg_no_action_slave_off_cmd);
+#endif
 	install_element(act, &cfg_action_pa_off_cmd);
 	install_element(act, &cfg_no_action_pa_off_cmd);
-#endif
 }
 
 int sysmobts_mgr_vty_init(void)

src/osmo-bts-sysmo/misc/sysmobts_misc.h

@@ -56,8 +56,9 @@ struct sbts2050_power_status {
 };
 
 int sbts2050_uc_check_temp(int *temp_pa, int *temp_board);
-void sbts2050_uc_set_power(int pmaster, int pslave, int ppa);
+int sbts2050_uc_set_power(int pmaster, int pslave, int ppa);
 int sbts2050_uc_get_status(struct sbts2050_power_status *status);
+int sbts2050_uc_set_pa_power(int on_off);
 void sbts2050_uc_initialize();
 
 #endif