From 911515b339109d4bdf992441d5efdf4a6f885f95 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Pali=20Roh=C3=A1r?= Date: Fri, 24 Sep 2021 23:07:10 +0200 Subject: [PATCH] tools: kwboot: Disable non-blocking mode MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 Signed-off-by: Marek Behún --- 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; -- 2.39.5