Hi Giacinto,
On 10/20/2018 05:13 AM, Giacinto Cifelli wrote:
Hi Denis,
On Mon, Sep 24, 2018 at 11:25 PM Denis Kenzior <[email protected]> wrote:
Hi Giacinto,
Besides, several modules use the option linux driver, which blocks in
case the port doesn't answer.
This single call:
g_at_chat_unref(port);
blocks either 30s or 1 minute, depending on the system. I might step
into it twice during my hardware initialization for several 3G models.
It helps to run this line on a separate thread unblocking the rest.
What system call blocks (use strace to determine this) ? If anything
inside the option driver blocks for 30-60 seconds, that is unacceptable
and needs to be fixed in the kernel.
I have finally had time to come back to this.
It is the close(fd), called in the g_lib that blocks.
I have further discovered that it is due to the fact that there are
write pending, and in this case a the closing_wait timeout kicks in.
I tried to remove this timeout with an udev rule, but it doesn't work.
I could set - still through udev, a call to the tool setserial, but it
doesn't seem proper, rules with scripts are heavy, and may also lead
to a wrong enumeration in udevng because some devices of the USB
enumeration are made available only after the rule has been executed.
I will study this a bit more. I'm surprised close can block a
O_NONBLOCK fd...
So, the code to fix this - in plugins/gemalto.c, would be:
#include <asm/ioctls.h>
#include <linux/serial.h>
int ioctl(int, int, void *);
static void closeport(gpointer user_data)
{
GAtChat *port = user_data;
GIOChannel *channel = g_at_chat_get_channel(port);
int fd = g_io_channel_unix_get_fd(channel);
struct serial_struct old, new;
g_at_chat_cancel_all(port);
g_at_chat_unregister_all(port);
ioctl(fd, TIOCGSERIAL, &old);
new = old;
new.closing_wait = ASYNC_CLOSING_WAIT_NONE;
ioctl(fd, TIOCSSERIAL, &new);
g_at_chat_unref(port);
}
do you see a better way to do it?
Can we simply add this setting to g_at_tty_open?
Regards,
-Denis
_______________________________________________
ofono mailing list
[email protected]
https://lists.ofono.org/mailman/listinfo/ofono
