firewire: cdev: add ioctls for iso resource management, amendment

Some fixes:
  - Remove stale documentation.
  - Fix a != vs. == thinko that got in the way of channel management.
  - Try bandwidth deallocation even if channel deallocation failed.

A simplification:
  - fw_cdev_allocate_iso_resource.channels is now ordered like
    libdc1394's dc1394_iso_allocate_channel() channels_allowed
    argument.

By the way, I looked closer at cards from NEC, TI, and VIA, and noticed
that they all don't implement IEEE 1394a behaviour which is meant to
deviate from IEEE 1212's notion of lock compare-swap.  This means that
we have to do two lock transactions instead of one in many cases where
one transaction would already succeed on a fully 1394a compliant IRM.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

1 files changed, 4 insertions, 6 deletions

diff --git a/include/linux/firewire-cdev.h b/include/linux/firewire-cdev.h
index 6ed9127680fd..2e35379bf96c 100644
--- a/include/linux/firewire-cdev.h
+++ b/include/linux/firewire-cdev.h
@@ -174,8 +174,6 @@ struct fw_cdev_event_iso_interrupt {
  * @handle:     Reference by which an allocated resource can be deallocated
  * @channel:    Isochronous channel which was (de)allocated, if any
  * @bandwidth:  Bandwidth allocation units which were (de)allocated, if any
- * @channels_available:  Last known availability of channels
- * @bandwidth_available: Last known availability of bandwidth
  *
  * An %FW_CDEV_EVENT_ISO_RESOURCE_ALLOCATED event is sent after an isochronous
  * resource was allocated at the IRM.  The client has to check @channel and
@@ -580,7 +578,7 @@ struct fw_cdev_get_cycle_timer {
  *
  * The %FW_CDEV_IOC_DEALLOCATE_ISO_RESOURCE_ONCE ioctl works like
  * %FW_CDEV_IOC_ALLOCATE_ISO_RESOURCE_ONCE except that resources are freed
- * instead of allocated.  At most one channel may be specified in this ioctl.
+ * instead of allocated.
  * An %FW_CDEV_EVENT_ISO_RESOURCE_DEALLOCATED event concludes this operation.
  *
  * To summarize, %FW_CDEV_IOC_DEALLOCATE_ISO_RESOURCE allocates iso resources
@@ -588,9 +586,9 @@ struct fw_cdev_get_cycle_timer {
  * In contrast, %FW_CDEV_IOC_ALLOCATE_ISO_RESOURCE_ONCE allocates iso resources
  * for the duration of a bus generation.
  *
- * @channels is a host-endian bitfield with the most significant bit
- * representing channel 0 and the least significant bit representing channel 63:
- * 1ULL << (63 - c)
+ * @channels is a host-endian bitfield with the least significant bit
+ * representing channel 0 and the most significant bit representing channel 63:
+ * 1ULL << c for each channel c that is a candidate for (de)allocation.
  *
  * @bandwidth is expressed in bandwidth allocation units, i.e. the time to send
  * one quadlet of data (payload or header data) at speed S1600.