[comp.os.minix] Second opinions.

johnc@rtmvax.UUCP (John Connin) (07/28/88)

I finally decided to give Minix's serial communications a whirl and
quickly found that it (updated to V1.3b) is missing characters at 1200.
To make a long story short, I decide to roll up my sleeves and investigate.
By accident I discovered that for every TTY read completion (console or
rs232), a get_time message is being set to the clock task.  In other words,
a simple <enter> at the command prompt will cause a get_time message to
be generated.

If my 1.3b update is correct, the source of the get_time messages is
the following code fragment from fs/read.c beginning on or about line 153.

    if (rw_flag == WRITING) {
        if (char_spec == 0 && block_spec == 0 && position > f_size)
            rip->i_size = position;
        rip->i_modtime = clock_time();               <<<<<<<
        rip->i_dirt = DIRTY;
    }

which I changed as follows:

    if (rw_flag == WRITING) {
        if (char_spec == 0 && block_spec == 0 && position > f_size) {
            rip->i_size = position;
            rip->i_modtime = clock_time();
            rip->i_dirt = DIRTY;
        }
    }

Lacking confidence at this point, I would be appreciative of any and all
second opinions regarding this change.  Does my original code conform
to version 1.3b?  Are there any undesireable side-effects resulting from
the above change?  etc...

BTW: Though the above change makes an improvement, I am still missing
characters at 1200 baud.