[media] media i.MX27 camera: improve discard buffer handling
[media] media i.MX27 camera: improve discard buffer handling

The way discard buffer was previously handled lead
to possible races that made a buffer that was not
yet ready to be overwritten by new video data. This
is easily detected at 25fps just adding "#define DEBUG"
to enable the "memset" check and seeing how the image
is corrupted.

A new "discard" queue and two discard buffers have
been added to make them flow trough the pipeline
of queues and thus provide suitable event ordering.

Signed-off-by: Javier Martin <bc650ed6f7e96f783596936e885b30ab9a703a6b@vista-silicon.com>
Signed-off-by: Guennadi Liakhovetski <50875182aae23d69ca7738697596f18a14e926fc@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <ad86ba2154032c9f55743a190faa2459a9d61d42@redhat.com>

TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas