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author | Lorenz Meier <lm@inf.ethz.ch> | 2014-04-20 21:04:05 +0200 |
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committer | Lorenz Meier <lm@inf.ethz.ch> | 2014-04-20 21:04:05 +0200 |
commit | 906abbcbb6215e9ae30c51efe3b813a71a963615 (patch) | |
tree | a777b178882a6d87439e5dfb73d163b5f7837999 /src/modules/mavlink | |
parent | f8232fa2698b37983f4c3f05926c9d6a7a107acf (diff) | |
download | px4-firmware-906abbcbb6215e9ae30c51efe3b813a71a963615.tar.gz px4-firmware-906abbcbb6215e9ae30c51efe3b813a71a963615.tar.bz2 px4-firmware-906abbcbb6215e9ae30c51efe3b813a71a963615.zip |
mavlink: Only write to TX buf if space is available. This is working around a NuttX issue where overflowing the TX buf leads to being unable to send any further data
Diffstat (limited to 'src/modules/mavlink')
-rw-r--r-- | src/modules/mavlink/mavlink_main.cpp | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/src/modules/mavlink/mavlink_main.cpp b/src/modules/mavlink/mavlink_main.cpp index a9f5f4de7..2d71bdce6 100644 --- a/src/modules/mavlink/mavlink_main.cpp +++ b/src/modules/mavlink/mavlink_main.cpp @@ -189,9 +189,18 @@ mavlink_send_uart_bytes(mavlink_channel_t channel, const uint8_t *ch, int length /* If the wait until transmit flag is on, only transmit after we've received messages. Otherwise, transmit all the time. */ if (instance->should_transmit()) { - ssize_t ret = write(uart, ch, desired); + + /* check if there is space in the buffer, let it overflow else */ + if (!ioctl(uart, FIONWRITE, (unsigned long)&buf_free)) { + + if (desired > buf_free) { + desired = buf_free; + } + } + + ssize_t ret = write(uart, ch, desired); if (ret != desired) { - // XXX do something here, but change to using FIONWRITE and OS buf size for detection + warnx("TX FAIL"); } } |