On 03/24/17 12:03, Jose Abreu wrote: > Hi Hans, > > > On 21-03-2017 11:49, Jose Abreu wrote: >> Hi all, >> >> This is a follow up patch from this discussion [1]. It should be >> seen more as a starting point to introduce better handling of >> time per frame in v4l2. Quoting Hans Verkuil from [1]: >> >> 1) "Add a flag V4L2_DV_FL_CAN_DETECT_REDUCED_FPS. If set, >> then the hw can detect the difference between regular fps >> and 1000/1001 fps. Note: this is only valid for timings of >> VIC codes with the V4L2_DV_FL_CAN_REDUCE_FPS flag set." >> >> 2) "Allow V4L2_DV_FL_REDUCED_FPS to be used for receivers >> if V4L2_DV_FL_CAN_DETECT_REDUCED_FPS is set." >> >> 3) "For standard VIC codes the pixelclock returned by >> query_dv_timings is that of the corresponding VIC timing, >> not what is measured. This will ensure fixed fps values" >> >> 4) "g_parm should calculate the fps based on the v4l2_bt_timings >> struct, looking at the REDUCES_FPS flags. For those receivers that >> cannot detect the difference, the fps will be 24/30/60 Hz, for >> those that can detect the difference g_parm can check if both >> V4L2_DV_FL_CAN_DETECT_REDUCED_FPS and V4L2_DV_FL_REDUCED_FPS are >> set and reduce the fps by 1000/1001." >> >> ----------- >> In terms of implementation: >> - Point 1) is done in patch 1/3 >> - Point 2) and 3) should be done by a HDMI Receiver driver >> (I think?). >> - Point 4) is done in patch 2/3. >> - The patch 3/3 is a simple implementation (which was not >> tested) in the cobalt driver >> ----------- >> >> [1] https://patchwork.kernel.org/patch/9609441/ >> >> Best regards, >> Jose Miguel Abreu >> >> Cc: Carlos Palminha <palminha@xxxxxxxxxxxx> >> Cc: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx> >> Cc: Hans Verkuil <hans.verkuil@xxxxxxxxx> >> Cc: linux-media@xxxxxxxxxxxxxxx >> Cc: linux-kernel@xxxxxxxxxxxxxxx >> >> Jose Abreu (3): >> [media] videodev2.h: Add new DV flag CAN_DETECT_REDUCED_FPS >> [media] v4l2-dv-timings: Introduce v4l2_calc_timeperframe helper >> [media] cobalt: Use v4l2_calc_timeperframe helper >> >> drivers/media/pci/cobalt/cobalt-v4l2.c | 9 +++++-- >> drivers/media/v4l2-core/v4l2-dv-timings.c | 39 +++++++++++++++++++++++++++++++ >> include/media/v4l2-dv-timings.h | 11 +++++++++ >> include/uapi/linux/videodev2.h | 7 ++++++ >> 4 files changed, 64 insertions(+), 2 deletions(-) >> > > Can you please review this series, when possible? And if you > could test it on cobalt it would be great :) Hopefully next week. Did you have some real-world numbers w.r.t. measured pixelclock frequencies and 60 vs 59.94 Hz and 24 vs 23.976 Hz? I do want to see that, since this patch series only makes sense if you can actually make use of it to reliably detect the difference. I will try to test that myself with cobalt, but almost certainly I won't be able to tell the difference; if memory serves it can't detect the freq with high enough precision. Regards, Hans
