Revert "media: cec-adap.c: drop activate_cnt, use state info instead"

This reverts commit 3e938b7d40 which is
commit f9222f8ca18bcb1d55dd749b493b29fd8092fb82 upstream.

It breaks the Android kernel abi and can be brought back in the future
in an abi-safe way if it is really needed.

Bug: 161946584
Change-Id: I16b7093a0a644af04a0c62aed235653bbeaae070
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

drivers/media/cec/core/cec-adap.c

@@ -1548,59 +1548,47 @@ static void cec_claim_log_addrs(struct cec_adapter *adap, bool block)
 }
 
 /*
- * Helper function to enable/disable the CEC adapter.
+ * Helper functions to enable/disable the CEC adapter.
  *
- * This function is called with adap->lock held.
+ * These functions are called with adap->lock held.
  */
-static int cec_adap_enable(struct cec_adapter *adap)
+static int cec_activate_cnt_inc(struct cec_adapter *adap)
 {
-	bool enable;
+	int ret;
-	int ret = 0;
 
-	enable = adap->monitor_all_cnt || adap->monitor_pin_cnt ||
+	if (adap->activate_cnt++)
-		 adap->log_addrs.num_log_addrs;
-	if (adap->needs_hpd)
-		enable = enable && adap->phys_addr != CEC_PHYS_ADDR_INVALID;
-
-	if (enable == adap->is_enabled)
 		return 0;
 
 	/* serialize adap_enable */
 	mutex_lock(&adap->devnode.lock);
-	if (enable) {
+	adap->last_initiator = 0xff;
-		adap->last_initiator = 0xff;
+	adap->transmit_in_progress = false;
-		adap->transmit_in_progress = false;
+	ret = call_op(adap, adap_enable, true);
-		ret = adap->ops->adap_enable(adap, true);
+	if (ret)
-		if (!ret) {
+		adap->activate_cnt--;
-			/*
-			 * Enable monitor-all/pin modes if needed. We warn, but
-			 * continue if this fails as this is not a critical error.
-			 */
-			if (adap->monitor_all_cnt)
-				WARN_ON(call_op(adap, adap_monitor_all_enable, true));
-			if (adap->monitor_pin_cnt)
-				WARN_ON(call_op(adap, adap_monitor_pin_enable, true));
-		}
-	} else {
-		/* Disable monitor-all/pin modes if needed (needs_hpd == 1) */
-		if (adap->monitor_all_cnt)
-			WARN_ON(call_op(adap, adap_monitor_all_enable, false));
-		if (adap->monitor_pin_cnt)
-			WARN_ON(call_op(adap, adap_monitor_pin_enable, false));
-		WARN_ON(adap->ops->adap_enable(adap, false));
-		adap->last_initiator = 0xff;
-		adap->transmit_in_progress = false;
-		adap->transmit_in_progress_aborted = false;
-		if (adap->transmitting)
-			cec_data_cancel(adap->transmitting, CEC_TX_STATUS_ABORTED, 0);
-	}
-	if (!ret)
-		adap->is_enabled = enable;
-	wake_up_interruptible(&adap->kthread_waitq);
 	mutex_unlock(&adap->devnode.lock);
 	return ret;
 }
 
+static void cec_activate_cnt_dec(struct cec_adapter *adap)
+{
+	if (WARN_ON(!adap->activate_cnt))
+		return;
+
+	if (--adap->activate_cnt)
+		return;
+
+	/* serialize adap_enable */
+	mutex_lock(&adap->devnode.lock);
+	WARN_ON(call_op(adap, adap_enable, false));
+	adap->last_initiator = 0xff;
+	adap->transmit_in_progress = false;
+	adap->transmit_in_progress_aborted = false;
+	if (adap->transmitting)
+		cec_data_cancel(adap->transmitting, CEC_TX_STATUS_ABORTED, 0);
+	mutex_unlock(&adap->devnode.lock);
+}
+
 /* Set a new physical address and send an event notifying userspace of this.
  *
  * This function is called with adap->lock held.
@@ -1621,16 +1609,33 @@ void __cec_s_phys_addr(struct cec_adapter *adap, u16 phys_addr, bool block)
 		adap->phys_addr = CEC_PHYS_ADDR_INVALID;
 		cec_post_state_event(adap);
 		cec_adap_unconfigure(adap);
-		if (becomes_invalid) {
+		if (becomes_invalid && adap->needs_hpd) {
-			cec_adap_enable(adap);
+			/* Disable monitor-all/pin modes if needed */
-			return;
+			if (adap->monitor_all_cnt)
+				WARN_ON(call_op(adap, adap_monitor_all_enable, false));
+			if (adap->monitor_pin_cnt)
+				WARN_ON(call_op(adap, adap_monitor_pin_enable, false));
+			cec_activate_cnt_dec(adap);
+			wake_up_interruptible(&adap->kthread_waitq);
 		}
+		if (becomes_invalid)
+			return;
+	}
+
+	if (is_invalid && adap->needs_hpd) {
+		if (cec_activate_cnt_inc(adap))
+			return;
+		/*
+		 * Re-enable monitor-all/pin modes if needed. We warn, but
+		 * continue if this fails as this is not a critical error.
+		 */
+		if (adap->monitor_all_cnt)
+			WARN_ON(call_op(adap, adap_monitor_all_enable, true));
+		if (adap->monitor_pin_cnt)
+			WARN_ON(call_op(adap, adap_monitor_pin_enable, true));
 	}
 
 	adap->phys_addr = phys_addr;
-	if (is_invalid)
-		cec_adap_enable(adap);
-
 	cec_post_state_event(adap);
 	if (adap->log_addrs.num_log_addrs)
 		cec_claim_log_addrs(adap, block);
@@ -1687,7 +1692,6 @@ int __cec_s_log_addrs(struct cec_adapter *adap,
 		      struct cec_log_addrs *log_addrs, bool block)
 {
 	u16 type_mask = 0;
-	int err;
 	int i;
 
 	if (adap->devnode.unregistered)
@@ -1703,7 +1707,8 @@ int __cec_s_log_addrs(struct cec_adapter *adap,
 		adap->log_addrs.osd_name[0] = '\0';
 		adap->log_addrs.vendor_id = CEC_VENDOR_ID_NONE;
 		adap->log_addrs.cec_version = CEC_OP_CEC_VERSION_2_0;
-		cec_adap_enable(adap);
+		if (!adap->needs_hpd)
+			cec_activate_cnt_dec(adap);
 		return 0;
 	}
 
@@ -1837,12 +1842,17 @@ int __cec_s_log_addrs(struct cec_adapter *adap,
 		       sizeof(log_addrs->features[i]));
 	}
 
+	if (!adap->needs_hpd && !adap->is_configuring && !adap->is_configured) {
+		int ret = cec_activate_cnt_inc(adap);
+
+		if (ret)
+			return ret;
+	}
 	log_addrs->log_addr_mask = adap->log_addrs.log_addr_mask;
 	adap->log_addrs = *log_addrs;
-	err = cec_adap_enable(adap);
+	if (adap->phys_addr != CEC_PHYS_ADDR_INVALID)
-	if (!err && adap->phys_addr != CEC_PHYS_ADDR_INVALID)
 		cec_claim_log_addrs(adap, block);
-	return err;
+	return 0;
 }
 
 int cec_s_log_addrs(struct cec_adapter *adap,
@@ -2145,9 +2155,20 @@ int cec_monitor_all_cnt_inc(struct cec_adapter *adap)
 	if (adap->monitor_all_cnt++)
 		return 0;
 
-	ret = cec_adap_enable(adap);
+	if (!adap->needs_hpd) {
-	if (ret)
+		ret = cec_activate_cnt_inc(adap);
+		if (ret) {
+			adap->monitor_all_cnt--;
+			return ret;
+		}
+	}
+
+	ret = call_op(adap, adap_monitor_all_enable, true);
+	if (ret) {
 		adap->monitor_all_cnt--;
+		if (!adap->needs_hpd)
+			cec_activate_cnt_dec(adap);
+	}
 	return ret;
 }
 
@@ -2158,7 +2179,8 @@ void cec_monitor_all_cnt_dec(struct cec_adapter *adap)
 	if (--adap->monitor_all_cnt)
 		return;
 	WARN_ON(call_op(adap, adap_monitor_all_enable, false));
-	cec_adap_enable(adap);
+	if (!adap->needs_hpd)
+		cec_activate_cnt_dec(adap);
 }
 
 /*
@@ -2173,9 +2195,20 @@ int cec_monitor_pin_cnt_inc(struct cec_adapter *adap)
 	if (adap->monitor_pin_cnt++)
 		return 0;
 
-	ret = cec_adap_enable(adap);
+	if (!adap->needs_hpd) {
-	if (ret)
+		ret = cec_activate_cnt_inc(adap);
+		if (ret) {
+			adap->monitor_pin_cnt--;
+			return ret;
+		}
+	}
+
+	ret = call_op(adap, adap_monitor_pin_enable, true);
+	if (ret) {
 		adap->monitor_pin_cnt--;
+		if (!adap->needs_hpd)
+			cec_activate_cnt_dec(adap);
+	}
 	return ret;
 }
 
@@ -2186,7 +2219,8 @@ void cec_monitor_pin_cnt_dec(struct cec_adapter *adap)
 	if (--adap->monitor_pin_cnt)
 		return;
 	WARN_ON(call_op(adap, adap_monitor_pin_enable, false));
-	cec_adap_enable(adap);
+	if (!adap->needs_hpd)
+		cec_activate_cnt_dec(adap);
 }
 
 #ifdef CONFIG_DEBUG_FS
@@ -2200,7 +2234,7 @@ int cec_adap_status(struct seq_file *file, void *priv)
 	struct cec_data *data;
 
 	mutex_lock(&adap->lock);
-	seq_printf(file, "enabled: %d\n", adap->is_enabled);
+	seq_printf(file, "activation count: %u\n", adap->activate_cnt);
 	seq_printf(file, "configured: %d\n", adap->is_configured);
 	seq_printf(file, "configuring: %d\n", adap->is_configuring);
 	seq_printf(file, "phys_addr: %x.%x.%x.%x\n",

include/media/cec.h

@@ -180,7 +180,6 @@ struct cec_adap_ops {
  * @needs_hpd:		if true, then the HDMI HotPlug Detect pin must be high
  *	in order to transmit or receive CEC messages. This is usually a HW
  *	limitation.
- * @is_enabled:		the CEC adapter is enabled
  * @is_configuring:	the CEC adapter is configuring (i.e. claiming LAs)
  * @is_configured:	the CEC adapter is configured (i.e. has claimed LAs)
  * @cec_pin_is_high:	if true then the CEC pin is high. Only used with the
@@ -191,6 +190,7 @@ struct cec_adap_ops {
  *	Drivers that need this can set this field to true after the
  *	cec_allocate_adapter() call.
  * @last_initiator:	the initiator of the last transmitted message.
+ * @activate_cnt:	number of times that CEC is activated
  * @monitor_all_cnt:	number of filehandles monitoring all msgs
  * @monitor_pin_cnt:	number of filehandles monitoring pin changes
  * @follower_cnt:	number of filehandles in follower mode
@@ -238,12 +238,12 @@ struct cec_adapter {
 
 	u16 phys_addr;
 	bool needs_hpd;
-	bool is_enabled;
 	bool is_configuring;
 	bool is_configured;
 	bool cec_pin_is_high;
 	bool adap_controls_phys_addr;
 	u8 last_initiator;
+	u32 activate_cnt;
 	u32 monitor_all_cnt;
 	u32 monitor_pin_cnt;
 	u32 follower_cnt;