diff options
| author | Antonio Ospite <ao2@ao2.it> | 2015-04-22 12:48:51 +0200 |
|---|---|---|
| committer | Chris Dickens <christopher.a.dickens@gmail.com> | 2015-04-27 01:47:01 -0700 |
| commit | 138d240858634fc14d379ac11f57020f9403185b (patch) | |
| tree | 2f166957360b53693bdc06181f40109ed7b17ee5 | |
| parent | 76b3d340d0d1fc0cdfa423492961f305a7be7866 (diff) | |
| download | libusb-138d240858634fc14d379ac11f57020f9403185b.tar.gz | |
core: generalize comment about setting configurations with claimed interfaces
The comment about libusb_set_configuration() failing when other programs
or drivers have claimed interfaces is valid whether or not the desired
configuration is _different_ from the current one, so generalize the
statement.
While at it also make it more explicit that in case of kernel drivers,
those must be detached from _all_ interfaces before a configuration can
be set.
Finally, move the item as last as the new details also suggest
a solution for when a lightweight reset is desired but kernel drivers
have claimed other interfaces, like in the fingerprint reader example
mentioned in the same section.
Signed-off-by: Antonio Ospite <ao2@ao2.it>
Signed-off-by: Chris Dickens <christopher.a.dickens@gmail.com>
| -rw-r--r-- | libusb/core.c | 7 | ||||
| -rw-r--r-- | libusb/version_nano.h | 2 |
2 files changed, 5 insertions, 4 deletions
diff --git a/libusb/core.c b/libusb/core.c index e72afcb..be658b0 100644 --- a/libusb/core.c +++ b/libusb/core.c @@ -223,9 +223,6 @@ struct list_head active_contexts_list; * -# If the device is already in the desired configuration, calling * libusb_set_configuration() using the same configuration value will cause * a lightweight device reset. This may not be desirable behaviour. - * -# libusb will be unable to change configuration if the device is in - * another configuration and other programs or drivers have claimed - * interfaces under that configuration. * -# In the case where the desired configuration is already active, libusb * may not even be able to perform a lightweight device reset. For example, * take my USB keyboard with fingerprint reader: I'm interested in driving @@ -234,6 +231,10 @@ struct list_head active_contexts_list; * Because the kernel has claimed an interface, it is not even possible to * perform the lightweight device reset, so libusb_set_configuration() will * fail. (Luckily the device in question only has a single configuration.) + * -# libusb will be unable to set a configuration if other programs or + * drivers have claimed interfaces. In particular, this means that kernel + * drivers must be detached from all the interfaces before + * libusb_set_configuration() may succeed. * * One solution to some of the above problems is to consider the currently * active configuration. If the configuration we want is already active, then diff --git a/libusb/version_nano.h b/libusb/version_nano.h index 17c3fd4..1de23d4 100644 --- a/libusb/version_nano.h +++ b/libusb/version_nano.h @@ -1 +1 @@ -#define LIBUSB_NANO 10971 +#define LIBUSB_NANO 10972 |