user/sven/linux.git/drivers/firewire/core.h, branch v3.2.73

atomic: use

2011-07-26T23:49:47Z

This allows us to move duplicated code in (atomic_inc_not_zero() for now) to Signed-off-by: Arun Sharma Reviewed-by: Eric Dumazet Cc: Ingo Molnar Cc: David Miller Cc: Eric Dumazet Acked-by: Mike Frysinger Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

firewire: sbp2: parallelize login, reconnect, logout

2011-05-10T20:53:46Z

The struct sbp2_logical_unit.work items can all be executed in parallel but are not reentrant. Furthermore, reconnect or re-login work must be executed in a WQ_MEM_RECLAIM workqueue. Hence replace the old single-threaded firewire-sbp2 workqueue by a concurrency-managed but non-reentrant workqueue with rescuer. firewire-core already maintains one, hence use this one. In earlier versions of this change, I observed occasional failures of parallel INQUIRY to an Initio INIC-2430 FireWire 800 to dual IDE bridge. More testing indicates that parallel INQUIRY is not actually a problem, but too quick successions of logout and login + INQUIRY, e.g. a quick sequence of cable plugout and plugin, can result in failed INQUIRY. This does not seem to be something that should or could be addressed by serialization. Another dual-LU device to which I currently have access to, an OXUF924DSB FireWire 800 to dual SATA bridge with firmware from MacPower, has been successfully tested with this too. This change is beneficial to environments with two or more FireWire storage devices, especially if they are located on the same bus. Management tasks that should be performed as soon and as quickly as possible, especially reconnect, are no longer held up by tasks on other devices that may take a long time, especially login with INQUIRY and sd or sr driver probe. Signed-off-by: Stefan Richter

firewire: core: use non-reentrant workqueue with rescuer

2011-05-10T20:53:45Z

firewire-core manages the following types of work items: fw_card.br_work: - resets the bus on a card and possibly sends a PHY packet before that - does not sleep for long or not at all - is scheduled via fw_schedule_bus_reset() by - firewire-ohci's pci_probe method - firewire-ohci's set_config_rom method, called by kernelspace protocol drivers and userspace drivers which add/remove Configuration ROM descriptors - userspace drivers which use the bus reset ioctl - itself if the last reset happened less than 2 seconds ago fw_card.bm_work: - performs bus management duties - usually does not (but may in corner cases) sleep for long - is scheduled via fw_schedule_bm_work() by - firewire-ohci's self-ID-complete IRQ handler tasklet - firewire-core's fw_device.work instances whenever the root node device was (successfully or unsuccessfully) discovered, refreshed, or rediscovered - itself in case of resource allocation failures or in order to obey the 125ms bus manager arbitration interval fw_device.work: - performs node probe, update, shutdown, revival, removal; including kernel driver probe, update, shutdown and bus reset notification to userspace drivers - usually sleeps moderately long, in corner cases very long - is scheduled by - firewire-ohci's self-ID-complete IRQ handler tasklet via the core's fw_node_event - firewire-ohci's pci_remove method via core's fw_destroy_nodes/ fw_node_event - itself during retries, e.g. while a node is powering up iso_resource.work: - accesses registers at the Isochronous Resource Manager node - usually does not (but may in corner cases) sleep for long - is scheduled via schedule_iso_resource() by - the owning userspace driver at addition and removal of the resource - firewire-core's fw_device.work instances after bus reset - itself in case of resource allocation if necessary to obey the 1000ms reallocation period after bus reset fw_card.br_work instances should not, and instances of the others must not, be executed in parallel by multiple CPUs -- but were not protected against that. Hence allocate a non-reentrant workqueue for them. fw_device.work may be used in the memory reclaim path in case of SBP-2 device updates. Hence we need a workqueue with rescuer and cannot use system_nrt_wq. Signed-off-by: Stefan Richter Reviewed-by: Tejun Heo

firewire: optimize iso queueing by setting wake only after the last packet

2011-05-10T20:53:45Z

When queueing iso packets, the run time is dominated by the two MMIO accesses that set the DMA context's wake bit. Because most drivers submit packets in batches, we can save much time by removing all but the last wakeup. The internal kernel API is changed to require a call to fw_iso_context_queue_flush() after a batch of queued packets. The user space API does not change, so one call to FW_CDEV_IOC_QUEUE_ISO must specify multiple packets to take advantage of this optimization. In my measurements, this patch reduces the time needed to queue fifty skip packets from userspace to one sixth on a 2.5 GHz CPU, or to one third at 800 MHz. Signed-off-by: Clemens Ladisch Signed-off-by: Stefan Richter

ALSA: add LaCie FireWire Speakers/Griffin FireWave Surround driver

2011-03-15T07:42:22Z

Add a driver for two playback-only FireWire devices based on the OXFW970 chip. v2: better AMDTP API abstraction; fix fw_unit leak; small fixes v3: cache the iPCR value v4: FireWave constraints; fix fw_device reference counting; fix PCR caching; small changes and fixes v5: volume/mute support; fix crashing due to pcm stop races v6: fix build; one-channel volume for LaCie v7: use signed values to make volume (range checks) work; fix function block IDs for volume/mute; always use channel 0 for LaCie volume Signed-off-by: Clemens Ladisch Acked-by: Stefan Richter Tested-by: Jay Fenlason Signed-off-by: Takashi Iwai

firewire: make PHY packet header format consistent

2010-12-13T19:39:14Z

Change the header of PHY packets to be sent to include a pseudo transaction code. This makes the header consistent with that of received PHY packets, and allows at_context_queue_packet() and log_ar_at_event() to see the packet type directly instead of having to deduce it from the header length or even from the header contents. Signed-off-by: Clemens Ladisch Signed-off-by: Stefan Richter

firewire: add isochronous multichannel reception

2010-07-29T21:09:18Z

This adds the DMA context programming and userspace ABI for multichannel reception, i.e. for listening on multiple channel numbers by means of a single DMA context. The use case is reception of more streams than there are IR DMA units offered by the link layer. This is already implemented by the older ohci1394 + ieee1394 + raw1394 stack. And as discussed recently on linux1394-devel, this feature is occasionally used in practice. The big drawbacks of this mode are that buffer layout and interrupt generation necessarily differ from single-channel reception: Headers and trailers are not stripped from packets, packets are not aligned with buffer chunks, interrupts are per buffer chunk, not per packet. These drawbacks also cause a rather hefty code footprint to support this rarely used OHCI-1394 feature. (367 lines added, among them 94 lines of added userspace ABI documentation.) This implementation enforces that a multichannel reception context may only listen to channels to which no single-channel context on the same link layer is presently listening to. OHCI-1394 would allow to overlay single-channel contexts by the multi-channel context, but this would be a departure from the present first-come-first-served policy of IR context creation. The implementation is heavily based on an earlier one by Jay Fenlason. Thanks Jay. Signed-off-by: Stefan Richter

firewire: cdev: add PHY pinging

2010-07-23T11:36:28Z

This extends the FW_CDEV_IOC_SEND_PHY_PACKET ioctl() for /dev/fw* to be useful for ping time measurements. One application for it would be gap count optimization in userspace that is based on ping times rather than hop count. (The latter is implemented in firewire-core itself but is not applicable to beta PHYs that act as repeater.) Signed-off-by: Stefan Richter

firewire: cdev: add PHY packet reception

2010-07-23T11:36:28Z

Add an FW_CDEV_IOC_RECEIVE_PHY_PACKETS ioctl() and FW_CDEV_EVENT_PHY_PACKET_RECEIVED poll()/read() event for /dev/fw*. This can be used to get information from remote PHYs by remote access PHY packets. This is also the 2nd half of the functionality (the receive part) to support a userspace implementation of a VersaPHY transaction layer. Safety considerations: - PHY packets are generally broadcasts, hence some kind of elevated privileges should be required of a process to be able to listen in on PHY packets. This implementation assumes that a process that is allowed to open the /dev/fw* of a local node does have this privilege. There was an inconclusive discussion about introducing POSIX capabilities as a means to check for user privileges for these kinds of operations. Other limitations: - PHY packet reception may be switched on by ioctl() but cannot be switched off again. It would be trivial to provide an off switch, but this is not worth the code. The client should simply close() the fd then, or just ignore further events. - For sake of simplicity of API and kernel-side implementation, no filter per packet content is provided. Signed-off-by: Stefan Richter

firewire: core: integrate software-forced bus resets with bus management

2010-07-13T07:58:27Z

Bus resets which are triggered - by the kernel drivers after updates of the local nodes' config ROM, - by userspace software via ioctl shall be deferred until after >=2 seconds after the last bus reset. If multiple modifications of the local nodes' config ROM happen in a row, only a single bus reset should happen after them. When the local node's link goes from inactive to active or vice versa, and at the two occasions of bus resets mentioned above --- and if the current gap count differs from 63 --- the bus reset should be preceded by a PHY configuration packet that reaffirms the gap count. Otherwise a bus manager would have to reset the bus again right after that. This is necessary to promote bus stability, e.g. leave grace periods for allocations and reallocations of isochronous channels and bandwidth, SBP-2 reconnections etc.; see IEEE 1394 clause 8.2.1. This change implements all of the above by moving bus reset initiation into a delayed work (except for bus resets which are triggered by the bus manager workqueue job and are performed there immediately). It comes with a necessary addition to the card driver methods that allows to get the current gap count from PHY registers. Signed-off-by: Stefan Richter