[PATCH 2/2] console: fix loose coupling between getchar and is_timeout delays

[Ahmad Fatoum]

We always want to run pollers while waiting in getchar().
This is already the case, because the delay chosen in getchar is the
minimum scheduling delay used in is_timeout.

To make the relation more obvious, define a constant for the minimum
scheduling delay and use it at both places.

Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
---
 common/clock.c         | 2 +-
 common/console.c       | 4 ++--
 include/clock.h        | 9 +++++++++
 include/linux/minmax.h | 1 +
 4 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/common/clock.c b/common/clock.c
index 931a96865140..87109f3efc2e 100644
--- a/common/clock.c
+++ b/common/clock.c
@@ -169,7 +169,7 @@ int is_timeout(uint64_t start_ns, uint64_t time_offset_ns)
 {
 	int ret = is_timeout_non_interruptible(start_ns, time_offset_ns);
 
-	if (time_offset_ns >= 100 * USECOND)
+	if (time_offset_ns >= SCHED_TIMEOUT_MIN)
 		resched();
 
 	return ret;
diff --git a/common/console.c b/common/console.c
index 24f1500a6558..393183a72514 100644
--- a/common/console.c
+++ b/common/console.c
@@ -548,8 +548,8 @@ int getchar(void)
 			start = get_time_ns();
 		}
 
-		if (is_timeout(start, 100 * USECOND) &&
-				kfifo_len(console_input_fifo))
+		if (is_timeout_interruptible(start, 100 * USECOND) &&
+		    kfifo_len(console_input_fifo))
 			break;
 	}
 
diff --git a/include/clock.h b/include/clock.h
index db20877571a4..ca69535e9185 100644
--- a/include/clock.h
+++ b/include/clock.h
@@ -4,6 +4,7 @@
 
 #include <types.h>
 #include <linux/time.h>
+#include <linux/minmax.h>
 #include <linux/bitops.h>
 
 #define SECOND (1000ULL * 1000 * 1000)
@@ -42,6 +43,14 @@ uint32_t clocksource_hz2mult(uint32_t hz, uint32_t shift_constant);
 int is_timeout(uint64_t start_ns, uint64_t time_offset_ns);
 int is_timeout_non_interruptible(uint64_t start_ns, uint64_t time_offset_ns);
 
+#define SCHED_TIMEOUT_MIN	(100 * USECOND)
+
+static inline int is_timeout_interruptible(uint64_t start_ns,
+					   uint64_t time_offset_ns)
+{
+	return is_timeout(start_ns, max(SCHED_TIMEOUT_MIN, time_offset_ns));
+}
+
 void arm_architected_timer_udelay(unsigned long us);
 
 void ndelay(unsigned long nsecs);
diff --git a/include/linux/minmax.h b/include/linux/minmax.h
index 9b6ddad7b3f6..8c114029d23a 100644
--- a/include/linux/minmax.h
+++ b/include/linux/minmax.h
@@ -2,6 +2,7 @@
 #ifndef _LINUX_MINMAX_H
 #define _LINUX_MINMAX_H
 
+#include <linux/compiler.h>
 #include <linux/const.h>
 
 /*
-- 
2.39.5