kernel/linux.git/include/linux/firewire-cdev.h, branch linux-2.6.35.y

firewire: cdev: prevent race between first get_info ioctl

2011-08-01T20:55:01+00:00

[ upstream commit 93b37905f70083d6143f5f4dba0a45cc64379a62 ] and bus reset event queuing Between open(2) of a /dev/fw* and the first FW_CDEV_IOC_GET_INFO ioctl(2) on it, the kernel already queues FW_CDEV_EVENT_BUS_RESET events to be read(2) by the client. The get_info ioctl is practically always issued right away after open, hence this condition only occurs if the client opens during a bus reset, especially during a rapid series of bus resets. The problem with this condition is twofold: - These bus reset events carry the (as yet undocumented) @closure value of 0. But it is not the kernel's place to choose closures; they are privat to the client. E.g., this 0 value forced from the kernel makes it unsafe for clients to dereference it as a pointer to a closure object without NULL pointer check. - It is impossible for clients to determine the relative order of bus reset events from get_info ioctl(2) versus those from read(2), except in one way: By comparison of closure values. Again, such a procedure imposes complexity on clients and reduces freedom in use of the bus reset closure. So, change the ABI to suppress queuing of bus reset events before the first FW_CDEV_IOC_GET_INFO ioctl was issued by the client. Note, this ABI change cannot be version-controlled. The kernel cannot distinguish old from new clients before the first FW_CDEV_IOC_GET_INFO ioctl. We will try to back-merge this change into currently maintained stable/ longterm series, and we only document the new behaviour. The old behavior is now considered a kernel bug, which it basically is. Signed-off-by: Stefan Richter Cc: Signed-off-by: Andi Kleen

firewire: cdev: fix cut+paste mistake in disclaimer

2010-04-15T20:18:36+00:00

This was supposed to be generic "authors or copyright holders"; I mistakenly picked up text from a wrong file. Reported-by: Daniel K. Signed-off-by: Stefan Richter

firewire: cdev: change license of exported header files to MIT license

2010-04-15T15:50:49+00:00

Among else, this allows projects like libdc1394 to carry copies of the ABI related header files without them or distributors having to worry about effects on the project's overall license terms. Switch to MIT license as suggested by Kristian. Also update the year in the copyright statement according to source history. Cc: Jay Fenlason Acked-by: Clemens Ladisch Signed-off-by: Stefan Richter Signed-off-by: Kristian Høgsberg

firewire: cdev: comment fixlet

2010-04-10T14:51:13+00:00

Signed-off-by: Stefan Richter

firewire: cdev: iso packet documentation

2010-04-10T14:51:13+00:00

Add the missing documentation for iso packets. Signed-off-by: Clemens Ladisch Signed-off-by: Stefan Richter

firewire: cdev: increment ABI version number

2010-02-24T19:36:55+00:00

so that clients can detect whether the FW_CDEV_IOC_GET_CYCLE_TIMER ioctl is reliable (on all tested controllers, especially the widely used VIA controllers, also NEC controllers, see commits b677532b and 1c1517ef). Also add a comment on the 2.6.32 iso xmit enhancement and on dual-buffer IR having been disabled in 2.6.33. Signed-off-by: Stefan Richter

firewire: cdev: add more flexible cycle timer ioctl

2010-02-24T19:36:54+00:00

The system time from CLOCK_REALTIME is not monotonic, hence problematic for the main user of the FW_CDEV_IOC_GET_CYCLE_TIMER ioctl. This issue exists in its successor ABI, i.e. raw1394, too. http://subversion.ffado.org/ticket/242 We now offer an alternative ioctl which lets the caller choose between CLOCK_REALTIME, CLOCK_MONOTONIC, and CLOCK_MONOTONIC_RAW as source of the local time, very similar to the clock_gettime libc function. The format of the local time return value matches that of clock_gettime (seconds and nanoseconds, instead of a single microseconds value from the existing ioctl). Signed-off-by: Stefan Richter

firewire: cdev: add_descriptor documentation fix

2010-01-26T19:54:50+00:00

struct fw_cdev_add_descriptor.length is in quadlets, not in bytes. Also remove any doubts about the endianess of descriptor data. Signed-off-by: Stefan Richter

firewire: fix use of multiple AV/C devices, allow multiple FCP listeners

2009-12-29T18:58:16+00:00

Control of more than one AV/C device at once --- e.g. camcorders, tape decks, audio devices, TV tuners --- failed or worked only unreliably, depending on driver implementation. This affected kernelspace and userspace drivers alike and was caused by firewire-core's inability to accept multiple registrations of FCP listeners. The fix allows multiple address handlers to be registered for the FCP command and response registers. When a request for these registers is received, all handlers are invoked, and the Firewire response is generated by the core and not by any handler. The cdev API does not change, i.e., userspace is still expected to send a response for FCP requests; this response is silently ignored. Signed-off-by: Clemens Ladisch Signed-off-by: Stefan Richter (changelog, rebased, whitespace)

firewire: cdev: add closure to async stream ioctl

2009-03-24T19:56:50+00:00

This changes the as yet unreleased FW_CDEV_IOC_SEND_STREAM_PACKET ioctl to generate an fw_cdev_event_response event just like the other two ioctls for asynchronous request transmission do. This way, clients get feedback on successful or unsuccessful transmission. This also adds input validation for length, tag, channel, sy, speed. Signed-off-by: Stefan Richter