From e688355bfeadf17ef522b1e62cc12f8e88e69667 Mon Sep 17 00:00:00 2001
From: Johan Hovold <jhovold@gmail.com>
Date: Mon, 6 Feb 2012 19:22:19 +0100
Subject: USB: serial: add macro for console error reporting
Add macro which prints an error message only once if port is used a
console.
Reporting errors in a write path when port is used as a console could
otherwise result in an infinite loop.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
include/linux/usb/serial.h | 15 +++++++++++++++
1 file changed, 15 insertions(+)
(limited to 'include')
diff --git a/include/linux/usb/serial.h b/include/linux/usb/serial.h
index 4267a9c717ba..10cb74d2ad1d 100644
--- a/include/linux/usb/serial.h
+++ b/include/linux/usb/serial.h
@@ -389,5 +389,20 @@ do { \
printk(KERN_DEBUG "%s: " format "\n", __FILE__, ##arg); \
} while (0)
+/*
+ * Macro for reporting errors in write path to avoid inifinite loop
+ * when port is used as a console.
+ */
+#define dev_err_console(usport, fmt, ...) \
+do { \
+ static bool __print_once; \
+ struct usb_serial_port *__port = (usport); \
+ \
+ if (!__port->port.console || !__print_once) { \
+ __print_once = true; \
+ dev_err(&__port->dev, fmt, ##__VA_ARGS__); \
+ } \
+} while (0)
+
#endif /* __LINUX_USB_SERIAL_H */
--
cgit