rt: Improve the serial console PASS_LIMIT

Beyond the warning:

 drivers/tty/serial/8250/8250.c:1613:6: warning: unused variable ‘pass_counter’ [-Wunused-variable]

the solution of just looping infinitely was ugly - up it to 1 million to
give it a chance to continue in some really ugly situation.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
index d465ace951867a8bb9d6401474d86bc04d11d053..c87df53df063f89ca8c6d5b943df92553ddfc370 100644 (file)
--- a/drivers/tty/serial/8250/8250_core.c
+++ b/drivers/tty/serial/8250/8250_core.c
@@ -81,7 +81,16 @@ static unsigned int skip_txen_test; /* force skip of txen test at init time */
 #define DEBUG_INTR(fmt...)     do { } while (0)
 #endif
 
-#define PASS_LIMIT     512
+/*
+ * On -rt we can have a more delays, and legitimately
+ * so - so don't drop work spuriously and spam the
+ * syslog:
+ */
+#ifdef CONFIG_PREEMPT_RT_FULL
+# define PASS_LIMIT    1000000
+#else
+# define PASS_LIMIT    512
+#endif
 
 #define BOTH_EMPTY     (UART_LSR_TEMT | UART_LSR_THRE)