Re: [PATCH v4 11/11] drm: rcar-du: Support interlaced video output through vsp1

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Kieran,

On Tuesday, 17 July 2018 23:32:56 EEST Kieran Bingham wrote:
> On 17/07/18 14:51, Laurent Pinchart wrote:
> > On Monday, 16 July 2018 20:20:30 EEST Kieran Bingham wrote:
> >> On 24/05/18 12:50, Laurent Pinchart wrote:
> >>> On Thursday, 3 May 2018 16:36:22 EEST Kieran Bingham wrote:
> >>>> Use the newly exposed VSP1 interface to enable interlaced frame support
> >>>> through the VSP1 lif pipelines.
> >>> 
> >>> s/lif/LIF/
> >> 
> >> Fixed.
> >> 
> >>>> Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
> >>>> ---
> >>>> 
> >>>>  drivers/gpu/drm/rcar-du/rcar_du_crtc.c | 1 +
> >>>>  drivers/gpu/drm/rcar-du/rcar_du_vsp.c  | 3 +++
> >>>>  2 files changed, 4 insertions(+)
> >>>> 
> >>>> diff --git a/drivers/gpu/drm/rcar-du/rcar_du_crtc.c
> >>>> b/drivers/gpu/drm/rcar-du/rcar_du_crtc.c index
> >>>> d71d709fe3d9..206532959ec9
> >>>> 100644
> >>>> --- a/drivers/gpu/drm/rcar-du/rcar_du_crtc.c
> >>>> +++ b/drivers/gpu/drm/rcar-du/rcar_du_crtc.c
> >>>> @@ -289,6 +289,7 @@ static void rcar_du_crtc_set_display_timing(struct
> >>>> rcar_du_crtc *rcrtc)
> >>>> 
> >>>>  	/* Signal polarities */
> >>>>  	value = ((mode->flags & DRM_MODE_FLAG_PVSYNC) ? DSMR_VSL : 0)
> >>>>  	
> >>>>  	      | ((mode->flags & DRM_MODE_FLAG_PHSYNC) ? DSMR_HSL : 0)
> >>>> 
> >>>> +	      | ((mode->flags & DRM_MODE_FLAG_INTERLACE) ? DSMR_ODEV : 0)
> >>> 
> >>> How will this affect Gen2 ?.
> >> 
> >> The bit is documented identically for Gen2. Potentially / Probably it
> >> 'might' reverse the fields... I'm not certain yet. I don't have access
> >> to a Gen2 platform to test.
> >> 
> >> I'll see if this change can be dropped, but I think it is playing a role
> >> in ensuring that the field detection occurs in VSP1 through the
> >> VI6_STATUS_FLD_STD() field. (see vsp1_dlm_irq_frame_end())
> >> 
> >>> Could you document what this change does in the
> >>> commit message ?
> >> 
> >> This sets the position in the buffer of the ODDF. With this set, the ODD
> >> field is located in the second half (BOTTOM) of the same frame of the
> >> interlace display.
> >> 
> >> Otherwise, it's in the first half (TOP)
> >> 
> >> I faced some issues as to the ordering when testing, so I suspect this
> >> might actually be related to that. (re VI6_STATUS_FLD_STD in
> >> vsp1_dlm_irq_frame_end()).
> >> 
> >> As you mention - this may have a negative effect on the Gen2
> >> implementation - so it needs considering with that.
> >> 
> >> 
> >> /me to investigate further.
> > 
> > Thank you. I don't object to this change, but I'd like to know what its
> > implications are on Gen2. It might even fix a bug :-) Let me know if you'd
> > like me to run tests on a Lager board.
> 
> I've done some testing with this (removing the DSMR change, and
> inverting the VI6_STATUS_FLD_STD handling) and had some odd results.
> Perhaps my testing needs refinement.
> 
> So, yes please - I think I'd really like to know what the effects are on
> a Lager platform.
> 
> Would you (or anyone with a Gen2 and interest in vsp1/du) be able to
> test my latest vsp1/du/interlaced branch/tag on your local Gen2 platform
> please?

I can test it when I'll come back home on the 24th (or rather on the next day 
as I'll land in the evening). Could you please ping me on the 25th ?

> I'm testing interlaced with:
> 
> kmstest # sanity test.
> kmstest -c 1 -r 1920x1080i --flip

My monitors don't support interlaced modes, so this won't be easy :-/

Also, what's the expected outcome of the above command in the working and non-
working cases ?

> Any (easy) other methods for testing interlaced pipelines are welcome.
> 
> Is it possible to set the mode for kmscube? (--help doesn't look promising)

Not that I know of, but I think that shouldn't be too difficult to add.

> I have various test streams of interlaced media content in my media
> library, but not an easy way of decoding and presenting these on the
> screen on the Gen3.
> 
> I believe GStreamer now has a drm/kms sink ... Perhaps I should get that
> recompiled. (That would help me with other tasks too actually)
> 
> >>>>  	      | DSMR_DIPM_DISP | DSMR_CSPM;
> >>>>  	
> >>>>  	rcar_du_crtc_write(rcrtc, DSMR, value);
> >>>> 
> >>>> diff --git a/drivers/gpu/drm/rcar-du/rcar_du_vsp.c
> >>>> b/drivers/gpu/drm/rcar-du/rcar_du_vsp.c index
> >>>> af7822a66dee..c7b37232ee91
> >>>> 100644
> >>>> --- a/drivers/gpu/drm/rcar-du/rcar_du_vsp.c
> >>>> +++ b/drivers/gpu/drm/rcar-du/rcar_du_vsp.c
> >>>> @@ -186,6 +186,9 @@ static void rcar_du_vsp_plane_setup(struct
> >>>> rcar_du_vsp_plane *plane)
> >>>>  	};
> >>>>  	unsigned int i;
> >>>> 
> >>>> +	cfg.interlaced = !!(plane->plane.state->crtc->mode.flags
> >>>> +			    & DRM_MODE_FLAG_INTERLACE);
> >>>> +
> >>>>  	cfg.src.left = state->state.src.x1 >> 16;
> >>>>  	cfg.src.top = state->state.src.y1 >> 16;
> >>>>  	cfg.src.width = drm_rect_width(&state->state.src) >> 16;

-- 
Regards,

Laurent Pinchart