Re: Switch a fd between blocking and non-blocking mode?

On Wed, Nov 13, 2019 at 4:59 AM Konstantin Andreev <andreev@swemel.ru> wrote:

I have looked into the sources of the kernel 4.19.13.

After the series of checks the fcntl(F_SETFL) just stores flags into the file descriptor, and that's all:

Ack, thanks. I did not think the kernel discarded the data when switching the mode. (a tcflush or tcdrain may do it, but I did not call them). I'm almost certain there's a bug in the firmware on the modem I am using. Jeff