Re: FreeBSD 8: libusb async mode + select(2) = nogo?
Hi On Fri, Jul 23, 2010 at 7:21 PM, Hans Petter Selasky wrote: > Should work, but it might be that the second poll, when you try to process the > events, don't work like expected. After any event on the two fd's you should > call "libusb_handle_events_locked()" using a "tv = NULL". Rewrote the program to use poll instead of select (which does fit libusb better even if I like select better generally) nothing else changed only poll instead of select. => Works like a charm So to sum it up: select + libusb seems not to work, poll + libusb works however. So is this a general FreeBSD select vs. poll issue or just with the USB stack? How can I help debug this further? Regards Peer Stritzinger ___ freebsd-usb@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-usb To unsubscribe, send any mail to "freebsd-usb-unsubscr...@freebsd.org"
Re: FreeBSD 8: libusb async mode + select(2) = nogo?
On Fri, Jul 23, 2010 at 7:21 PM, Hans Petter Selasky wrote: > Should work, but it might be that the second poll, when you try to process the > events, don't work like expected. After any event on the two fd's you should > call "libusb_handle_events_locked()" using a "tv = NULL". With libusb_handle_events_locked() instead of libusb_handle_events_timeout() there is no improvement ... It looks like if there is a IN alread pending on the bus when program runs the first select call returns the filedesc correctly but after this nothing triggers the second select. At least most of the time it looks like IN transfers that are received during the second select are somehow swallowed unhandled. If there is no IN pending on the bus the first select also returns but libusb_handle_events_locked() doesn't call a callback, then the second select also fails. Regards -- Peer Could it be that after the poll() in lib_usb_handle_events_*() libusb or the usb stack is somewhat in a corrupt state? ___ freebsd-usb@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-usb To unsubscribe, send any mail to "freebsd-usb-unsubscr...@freebsd.org"
Re: FreeBSD 8: libusb async mode + select(2) = nogo?
Hi,
On Fri, Jul 23, 2010 at 7:21 PM, Hans Petter Selasky wrote:
> Should work, but it might be that the second poll, when you try to process the
> events, don't work like expected. After any event on the two fd's you should
> call "libusb_handle_events_locked()" using a "tv = NULL".
Added some debug printing to make watching these easier:
active config: num_interfaces: 1
interface 0: num_altsetting: 1
if_desc 0: n_ep=4 if_nr=0
max packet on 3.2.6 = 512
setup_usb_fds: read 3
setup_usb_fds: read 6
setup_usb_fds: write 6
setup_usb_fds: nfds 6
calling select ...
returned 1 -> so select returns once (always as it looks)
check_usb_fds: found desc 3 in readfds
calling libusb_handle_events_timeout
transfer_completed: actual_len: 52-> and also gets a transfer from
the usb (this resubmits the IN transfer)
setup_usb_fds: read 3
setup_usb_fds: read 6
setup_usb_fds: write 6
setup_usb_fds: nfds 6
calling select ...-> but here it hangs until a signal
The code that did output this still using libusb_handle_events_timeout()
rv = libusb_submit_transfer(tr);
assert(rv == 0);
sp.pollfds = libusb_get_pollfds(ctx);
while (1)
{
timeout_pending = libusb_get_next_timeout(ctx, &timeout);
setup_usb_fds (&sp);
printf("calling select ...\n");
rv = select(sp.nfds, &sp.readfds, &sp.writefds, &sp.exceptfds,
(timeout_pending) ? &timeout : NULL);
printf("returned %d\n", rv);
assert (rv >= 0 || errno == EINTR);
if (rv == 0 || (rv > 0 && check_usb_fds (&sp)))
{
printf ("calling libusb_handle_events_timeout\n");
libusb_handle_events_timeout(ctx, NULL);
}
}
-- Peer
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Re: FreeBSD 8: libusb async mode + select(2) = nogo?
Hi, On Fri, Jul 23, 2010 at 7:21 PM, Hans Petter Selasky wrote: > > Should work, but it might be that the second poll, when you try to process the > events, don't work like expected. After any event on the two fd's you should > call "libusb_handle_events_locked()" using a "tv = NULL". I was calling libusb_handle_events_timeout(ctx, NULL), does this make an difference (only running single threaded) -- Peer ___ freebsd-usb@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-usb To unsubscribe, send any mail to "freebsd-usb-unsubscr...@freebsd.org"
Re: FreeBSD 8: libusb async mode + select(2) = nogo?
On Friday 23 July 2010 19:12:46 Peer Stritzinger wrote:
> Hi,
>
> On Fri, Jul 23, 2010 at 4:57 PM, Hans Petter Selasky
wrote:
> > What are the polling flags you are using?
>
> Do you mean the libusb_pollfd entries?
>
> They are:
>
> {fd = 0x7, events = 0x1}
> {fd = 0xc, events = 0x45}
>
> I translate these into select(2) params like this:
>
> nfds = 0xc, readfds = {__fds_bits = {0x1080, 0x0 }},
> writefds = {__fds_bits = {0x1000, 0x0 }}, exceptfds = {
> __fds_bits = {0x0 }},
>
> And call select with timeout = NULL (since libusb_get_next_timeout returned
> 0)
Should work, but it might be that the second poll, when you try to process the
events, don't work like expected. After any event on the two fd's you should
call "libusb_handle_events_locked()" using a "tv = NULL".
--HPS
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Re: FreeBSD 8: libusb async mode + select(2) = nogo?
Hi,
On Fri, Jul 23, 2010 at 4:57 PM, Hans Petter Selasky wrote:
>
> What are the polling flags you are using?
Do you mean the libusb_pollfd entries?
They are:
{fd = 0x7, events = 0x1}
{fd = 0xc, events = 0x45}
I translate these into select(2) params like this:
nfds = 0xc, readfds = {__fds_bits = {0x1080, 0x0 }},
writefds = {__fds_bits = {0x1000, 0x0 }}, exceptfds = {
__fds_bits = {0x0 }},
And call select with timeout = NULL (since libusb_get_next_timeout returned 0)
Regards
-- Peer
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Re: FreeBSD 8: libusb async mode + select(2) = nogo?
On Friday 23 July 2010 15:36:14 Peer Stritzinger wrote: > Hi, > > I'm using libusb to talk to a generic device (thats being also > developed by me), synchronous works fine now. > > Asynchronous mode with blocking libusb_handle_events() works also. > > Now I'm trying to also talk to non USB file descriptors. For this I'm > using select(2), filling the sets from libusb_get_pollfds() results. > > Somehow the select call never returns (no timeouts), if It gets some > external trigger (like stopping in the debugger can continuing) it > returns and has plausible return values. > > Looking into libusb I find that it uses poll(2) internally. > > Is select(2) supposed to work with libusb fd'? > > Should I rather use poll(2)? (I do like select more -- more BSDish). > What are the polling flags you are using? --HPS ___ freebsd-usb@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-usb To unsubscribe, send any mail to "freebsd-usb-unsubscr...@freebsd.org"
FreeBSD 8: libusb async mode + select(2) = nogo?
Hi, I'm using libusb to talk to a generic device (thats being also developed by me), synchronous works fine now. Asynchronous mode with blocking libusb_handle_events() works also. Now I'm trying to also talk to non USB file descriptors. For this I'm using select(2), filling the sets from libusb_get_pollfds() results. Somehow the select call never returns (no timeouts), if It gets some external trigger (like stopping in the debugger can continuing) it returns and has plausible return values. Looking into libusb I find that it uses poll(2) internally. Is select(2) supposed to work with libusb fd'? Should I rather use poll(2)? (I do like select more -- more BSDish). Best regards Peer Stritzinger ___ freebsd-usb@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-usb To unsubscribe, send any mail to "freebsd-usb-unsubscr...@freebsd.org"
