ARM: 9480/1: entry: expand comment in __switch_tografted

As per discussion between the developers in the mail thread
linked, expand the comment in __switch_to so that readers
of the code understand what is going on.

Suggested-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Linus Walleij <linusw@kernel.org>>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

3 files changed, 29 insertions, 0 deletions

diff --git a/samples/watchdog/.gitignore b/samples/watchdog/.gitignore
new file mode 100644
index 000000000..a70a0150e
--- /dev/null
+++ b/samples/watchdog/.gitignore
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+/watchdog-simple
diff --git a/samples/watchdog/Makefile b/samples/watchdog/Makefile
new file mode 100644
index 000000000..ab39d23dc
--- /dev/null
+++ b/samples/watchdog/Makefile
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0
+userprogs-always-y += watchdog-simple
diff --git a/samples/watchdog/watchdog-simple.c b/samples/watchdog/watchdog-simple.c
new file mode 100644
index 000000000..9ce66d2ca
--- /dev/null
+++ b/samples/watchdog/watchdog-simple.c
@@ -0,0 +1,25 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <fcntl.h>
+
+int main(void)
+{
+	int fd = open("/dev/watchdog", O_WRONLY);
+	int ret = 0;
+	if (fd == -1) {
+		perror("watchdog");
+		exit(EXIT_FAILURE);
+	}
+	while (1) {
+		ret = write(fd, "\0", 1);
+		if (ret != 1) {
+			ret = -1;
+			break;
+		}
+		sleep(10);
+	}
+	close(fd);
+	return ret;
+}