From: Pali Rohár pali@kernel.org
The kwboot utility does not handle EAGAIN / EBUSY errors, it expects blocking mode on tty - it uses select() to check if data is available.
Disable non-blocking mode by clearing O_NDELAY flag which was set by open().
We can't just take O_NDELAY from open(), because it is required there until the CLOCAL flag is set on the tty.
Signed-off-by: Pali Rohár pali@kernel.org Signed-off-by: Marek Behún marek.behun@nic.cz --- tools/kwboot.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/tools/kwboot.c b/tools/kwboot.c index a527c79cf3..5e491f31a4 100644 --- a/tools/kwboot.c +++ b/tools/kwboot.c @@ -639,7 +639,7 @@ baud_fail: static int kwboot_open_tty(const char *path, int baudrate) { - int rc, fd; + int rc, fd, flags; struct termios tio;
rc = -1; @@ -661,6 +661,14 @@ kwboot_open_tty(const char *path, int baudrate) if (rc) goto out;
+ flags = fcntl(fd, F_GETFL); + if (flags < 0) + goto out; + + rc = fcntl(fd, F_SETFL, flags & ~O_NDELAY); + if (rc) + goto out; + rc = kwboot_tty_change_baudrate(fd, baudrate); if (rc) goto out;