linux-hardened/drivers/media
Laurent Pinchart 310fe52461 V4L/DVB (13827): uvcvideo: Switch to a monotonic clock for V4L2 buffers timestamps
The realtime clock provided by do_gettimeofday() is affected by time
jumps caused by NTP or DST. Furthermore, preliminary investigation
showed that SMP systems the realtime clock is based on the CPU TSC,
and those could get slightly out of sync, resulting in jitter in the
timestamps depending on which processor handles the USB interrupts.

Instead of the realtime clock, use a monotonic high resolution clock to
timestamp the buffer. As this could in theory introduce a regression
with some userspace applications expecting a realtime clock timestamp,
add a module parameter to switch back to the realtime clock.

Thanks to Paulo Assis for pointing out and investigating the issue.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2010-02-26 15:10:24 -03:00
..
common saa7146: stop DMA before de-allocating DMA scatter/gather page buffers 2010-02-01 22:02:03 -02:00
dvb V4L/DVB (13818): Add Prof 7500 DVB-S2 USB card 2010-02-26 15:10:24 -03:00
IR V4L/DVB (13825): ir-core: Don't OOPS if IR device props is not defined 2010-02-26 15:10:24 -03:00
radio V4L/DVB (13690): radio/si470x: #include <sched.h> 2009-12-16 09:28:00 -02:00
video V4L/DVB (13827): uvcvideo: Switch to a monotonic clock for V4L2 buffers timestamps 2010-02-26 15:10:24 -03:00
Kconfig V4L/DVB (13612): IR: Move common IR code to drivers/media/IR 2009-12-16 00:18:42 -02:00
Makefile V4L/DVB (13612): IR: Move common IR code to drivers/media/IR 2009-12-16 00:18:42 -02:00