On 24.09.21 23:07, Marek Behún wrote:
From: Marek Behún marek.behun@nic.cz
The tcsetattr() function can return 0 even if baudrate was not changed. Check whether baudrate was changed to requested value, and in case of arbitrary baudrate, check whether the set value is within 3% tolerance.
Signed-off-by: Marek Behún marek.behun@nic.cz
Reviewed-by: Stefan Roese sr@denx.de
Thanks, Stefan
tools/kwboot.c | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+)
diff --git a/tools/kwboot.c b/tools/kwboot.c index 7ccab2993f..d8b950787b 100644 --- a/tools/kwboot.c +++ b/tools/kwboot.c @@ -567,6 +567,13 @@ kwboot_tty_baudrate_to_speed(int baudrate) } }
+static int +_is_within_tolerance(int value, int reference, int tolerance) +{
- return 100 * value >= reference * (100 - tolerance) &&
100 * value <= reference * (100 + tolerance);+}
- static int kwboot_tty_change_baudrate(int fd, int baudrate) {
@@ -601,7 +608,32 @@ kwboot_tty_change_baudrate(int fd, int baudrate) if (rc) return rc;
- rc = tcgetattr(fd, &tio);
- if (rc)
return rc;- if (cfgetospeed(&tio) != speed || cfgetispeed(&tio) != speed)
goto baud_fail;+#ifdef BOTHER
- /*
* Check whether set baudrate is within 3% tolerance.* If BOTHER is defined, Linux always fills out c_ospeed / c_ispeed* with real values.*/- if (!_is_within_tolerance(tio.c_ospeed, baudrate, 3))
goto baud_fail;- if (!_is_within_tolerance(tio.c_ispeed, baudrate, 3))
goto baud_fail;+#endif
- return 0;
+baud_fail:
fprintf(stderr, "Could not set baudrate to requested value\n");
errno = EINVAL;
return -1; }
static int
Viele Grüße, Stefan