kernel/linux.git/drivers/staging/line6, branch v3.4.55

staging: line6: separate handling of buffer allocation and stream startup

2012-02-09T17:14:35+00:00

There are several features of the Line6 USB driver which require PCM data to be exchanged with the device: *) PCM playback and capture via ALSA *) software monitoring (for devices without hardware monitoring) *) optional impulse response measurement However, from the device's point of view, there is just a single capture and playback stream, which must be shared between these subsystems. It is therefore necessary to maintain the state of the subsystems with respect to PCM usage. We define several constants of the form LINE6_BIT_PCM___ with the following meanings: *) is one of -) ALSA: PCM playback and capture via ALSA -) MONITOR: software monitoring -) IMPULSE: optional impulse response measurement *) is one of -) PLAYBACK: audio output (from host to device) -) CAPTURE: audio input (from device to host) *) is one of -) BUFFER: buffer required by PCM data stream -) STREAM: actual PCM data stream The subsystems call line6_pcm_acquire() to acquire the (shared) resources needed for a particular operation (e.g., allocate the buffer for ALSA playback or start the capture stream for software monitoring). When a resource is no longer needed, it is released by calling line6_pcm_release(). Buffer allocation and stream startup are handled separately to allow the ALSA kernel driver to perform them at appropriate places (since the callback which starts a PCM stream is not allowed to sleep). Signed-off-by: Markus Grabner Signed-off-by: Greg Kroah-Hartman

staging: line6: use source select control for UX2 devices

2012-02-09T17:14:35+00:00

Signed-off-by: Markus Grabner Signed-off-by: Greg Kroah-Hartman

staging: line6: removed obsolete code

2012-02-09T17:14:35+00:00

Signed-off-by: Markus Grabner Signed-off-by: Greg Kroah-Hartman

staging: line6: fixed ALSA/PCM interaction

2011-12-10T03:26:09+00:00

The PCM subsystem in the Line6 driver is mainly used for PCM playback and capture by ALSA, but also has other tasks, most notably providing a low-latency software monitor for devices which don't support hardware monitoring (e.g., the TonePort series). This patch makes ALSA "play nicely" with the other components, i.e., prevents it from resetting the isochronous USB transfer while other PCM tasks (software monitoring) are running. Signed-off-by: Markus Grabner Signed-off-by: Greg Kroah-Hartman

staging: line6: wait for urbs in snd_line6_prepare()

2011-12-10T03:26:09+00:00

The .trigger() pcm callbacks are not allowed to block and cannot wait until urbs have completed. We need to ensure that stopping, preparing, and then restarting a stream always works. Currently the driver will sometimes return -EBUSY when restarting the stream because urbs have not completed yet. This can be triggered by jackd from userspace. The solution is to wait on urbs in the .prepare() pcm callback since blocking is allowed in that callback. This guarantees that all urbs are quiesced and ready to be submitted when the start trigger callback is invoked. Signed-off-by: Stefan Hajnoczi Signed-off-by: Markus Grabner Signed-off-by: Greg Kroah-Hartman

staging: line6: eliminate useless NULL checks

2011-12-10T03:26:09+00:00

The line6 driver checks struct field addresses for NULL where it does not make sense to do so. The struct has already been checked for NULL and there is no value in checking the first field's address too. Suggested-by: Dan Carpenter Signed-off-by: Stefan Hajnoczi Signed-off-by: Markus Grabner Signed-off-by: Greg Kroah-Hartman

staging: line6: eliminate useless index_out variable

2011-12-10T03:26:09+00:00

Playback urbs use the index_out counter to decide which part of the playback buffer to use. Since the urb already has a unique index in range [0, LINE6_ISO_BUFFERS) there is no need to keep a separate counter. Use the urb index instead. This also eliminates the possibility of two urbs using the same playback buffer space if they ever complete out-of-order for some reason. Signed-off-by: Stefan Hajnoczi Signed-off-by: Markus Grabner Signed-off-by: Greg Kroah-Hartman

staging: line6: fix playback urb transfer buffer calculation

2011-12-10T03:26:09+00:00

The playback urb transfer buffer calculation does not factor in LINE6_ISO_PACKETS. Buffer memory is organized like this in the driver: Buffer 0 Buffer 1 ... [Packet 0, Packet 1, ...][Packet 0, Packet 1, ...][Packet 0, ...] However, we're lucky that LINE6_ISO_PACKETS is currently defined as 1 so this patch does not change any behavior. It's still worth including this fix in case the LINE6_ISO_PACKETS value is changed in the future. Signed-off-by: Stefan Hajnoczi Signed-off-by: Markus Grabner Signed-off-by: Greg Kroah-Hartman

staging: line6: fix memory leak in .hw_params()

2011-12-10T03:26:09+00:00

The .hw_params() pcm callback can be invoked multiple times in a row. Ensure that the URB data buffer is only allocated once. Signed-off-by: Stefan Hajnoczi Signed-off-by: Markus Grabner Signed-off-by: Greg Kroah-Hartman

staging/line6: refactor device information and add POD HD 500

2011-12-08T20:33:49+00:00

This patch refactors the device information code and adds preliminary support for the POD HD 500 device. Signed-off-by: Markus Grabner Signed-off-by: Greg Kroah-Hartman