Darwin: interrupt and isochronous transfers don't timeout

[mikef]

I created the following patch that fixes the issue discussed here:

​http://old.nabble.com/Timeout-parameter-in-libusb_interrupt_transfer%28%29-doesn%27t-work-as-expected-td27003929.html

I messed something up and my response ended up here:

​http://old.nabble.com/Re%3A-Timeout-parameter-in-libusb_interrupt_transfer%28%29-doesn%27t-work-as-expected-td27660317.html

[mikef]

Patch to io.c and sync.c

[mikef]

Removes the USBI_OS_HANDLES_TIMEOUT for Mac OS X

[mikef]

Original patch (0001-Fixed-io.c-and-sync.c-so-that-libusb-timeouts-are-ha.patch) had the possibilty of affecting the external API.

Developed alternate patch: 0001-Removed-the-USBI_OS_HANDLES_TIMEOUT-assumption-and-c.patch

[hjelmn]

This bug should be fixed in the next release. I didn't want to remove the USBI_OS_HANDLES_TIMEOUT assumption so I changed the granularity so libusb will known to abort interrupt and isochronous timeouts since the os does not support timeouts on these endpoints.

[ludovicrousseau]

Is the bug (supposed to be) fixed in git now?

I tried with a version up-to-date (latest commit 116d34f608b02f4e14668450b158acf5db726f95) and libusb_handle_events() does not handle/report a timeout on Mac OS X for an interrupt end point.

[ludovicrousseau]

In fact libusb_handle_events() does timeout but every 60 seconds only. This is the default timeout defined in libusb_handle_events().

So the timeout set in libusb_fill_bulk_transfer() is not used :-(

[ludovicrousseau]

Simple (temporary) patch:

-10-13 16:02:34.000000000 +0200
+++ configure.ac    2010-10-13 15:55:44.000000000 +0200
@@ -54,7 +54,7 @@ case $host in
    AC_DEFINE(OS_DARWIN, [], [Darwin backend])
    AC_SUBST(OS_DARWIN)
    AC_DEFINE([THREADS_POSIX], [], [Use Posix Threads])
-   AC_DEFINE(USBI_OS_HANDLES_TIMEOUT, [], [Backend handles timeout])
+   #AC_DEFINE(USBI_OS_HANDLES_TIMEOUT, [], [Backend handles timeout])
    AC_MSG_RESULT([Darwin/MacOS X])
    backend="darwin"
    threads="posix"

[hjelmn]

The fix has been sent in to the mailing list but not applied. Take a look and give them a try.

[ludovicrousseau]

Another patch is available at ​http://libusb.6.n5.nabble.com/PATCH-darwin-2-4-Darwin-Fix-isoch-interrupt-timeouts-tt3200715.html#a3200715 but not yet committed to git.

[Nathan Hjelm <hjelmn@…>]

In [67d9ef7b6877e17f2deec81cd41dc0948f6bed4b/libusb]:

Remove USBI_OS_HANDLES_TIMEOUT and fix int/isoc timeouts on Darwin

Backends set USBI_TRANSFER_OS_HANDLES_TIMEOUT for transfers instead.
Darwin only handles timeouts for bulk and control transfers, so the
backend now sets that flag accordingly, making libusb core handle
timeouts for interrupt and isochronous transfers. Fixes #31.

Signed-off-by: Nathan Hjelm <hjelmn@…>

[stuge: rework libusb_get_next_timeout() and enum usbi_transfer_flags]
[stuge: fix typo; set USBI_TRANSFER_TIMED_OUT flag correctly]