trigger [incompatibility]: push_block mandatory

The trigger operation push_block() is mandatory in order to use a
trigger on output csets

Signed-off-by: Federico Vaga <federico.vaga@gmail.com>
Acked-by: Alessandro Rubini <rubini@gnudd.com>
triggers/zio-trig-hrt.c: fix fire on re-enable

bug: on re-enable it automatically fires even if no timer was programmed
or it was already expired. Here the most simple procedure to
reproduce the bug:

insmod zio-zero.ko
cd /sys/bus/zio/devices/zzero-0000/zero-input-8
echo hrt > current_trigger
echo 0 > trigger/enable
echo 1 > trigger/enable

the trigger fired and you will find a block in all buffers.

Signed-off-by: Federico Vaga <federico.vaga@gmail.com>
Acked-by: Alessandro Rubini <rubini@gnudd.com>
zio: add current len and kb sysfs buf attribute

This patch add two new attributes: "allocated-buffer-len" and
"allocated-buffer-kb". Buffers are expected to use one of them, or both.

The purpose of these attribute is to export to user space information about
the number of blocks stored in a buffer. This information can be used to
monitor buffer status, and see how the data flow behaves.

We report the allocated buffer size, which includes active blocks,
instead of the size currently stored, because it reflects actual use
of the available data space (the max-buffer-* attributes). Knowing how
many blocks, or kilobytes, are currently stored is much less
important.

Signed-off-by: Federico Vaga <federico.vaga@gmail.com>
Acked-by: Alessandro Rubini <rubini@gnudd.com>
buffers: use alloc_len and alloc_kb sysfs attribute

Signed-off-by: Federico Vaga <federico.vaga@gmail.com>
Acked-by: Alessandro Rubini <rubini@gnudd.com>
zio.h and doc: introduce ZIO_CSET_TYPE_RAW

Signed-off-by: Alessandro Rubini <rubini@gnudd.com>
Acked-by: Federico Vaga <federico.vaga@gmail.com>