[PATCH v2 2/7] console: Keep ->start() and ->stop() balanced

[Andy Shevchenko <andriy.shevchenko@linux.intel.com>]

There is no need to call ->start() for already started device. All the same,
there is no need to call ->stop() for devices still in use.

For now enforce this only for CONSOLE_MUX case.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
v2: new patch
 common/console.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/common/console.c b/common/console.c
index 1efbcc7672ce..b051c24e7389 100644
--- a/common/console.c
+++ b/common/console.c
@@ -174,6 +174,16 @@ static struct stdio_dev *tstcdev;
 struct stdio_dev **console_devices[MAX_FILES];
 int cd_count[MAX_FILES];
 
+static bool console_needs_handle(int file, struct stdio_dev *dev)
+{
+	int i;
+
+	for (i = 0; i < cd_count[file]; i++)
+		if (console_devices[file][i] == dev)
+			return false;
+	return true;
+}
+
 /*
  * This depends on tstc() always being called before getchar().
  * This is guaranteed to be true because this routine is called
@@ -272,6 +282,11 @@ static inline void console_doenv(int file, struct stdio_dev *dev)
 }
 #endif
 #else
+static inline bool console_needs_handle(int file, struct stdio_dev *dev)
+{
+	return true;
+}
+
 static inline int console_getc(int file)
 {
 	return stdio_devices[file]->getc(stdio_devices[file]);
@@ -310,6 +325,9 @@ int console_start(int file, struct stdio_dev *dev)
 {
 	int error;
 
+	if (!console_needs_handle(file, dev))
+		return 0;
+
 	/* Start new device */
 	if (dev->start) {
 		error = dev->start(dev);
@@ -322,6 +340,9 @@ int console_start(int file, struct stdio_dev *dev)
 
 void console_stop(int file, struct stdio_dev *dev)
 {
+	if (!console_needs_handle(file, dev))
+		return;
+
 	if (dev->stop)
 		dev->stop(dev);
 }
-- 
2.29.2