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Feedback-ID: i8771445c:Fastmail
Date:   Thu, 18 Aug 2022 17:31:01 +0200
From:   Maxime Ripard <maxime@cerno.tech>
To:     Noralf =?utf-8?Q?Tr=C3=B8nnes?= <noralf@tronnes.org>
Cc:     Jernej Skrabec <jernej.skrabec@gmail.com>,
        Martin Blumenstingl <martin.blumenstingl@googlemail.com>,
        Chen-Yu Tsai <wens@csie.org>,
        Philipp Zabel <p.zabel@pengutronix.de>,
        Jerome Brunet <jbrunet@baylibre.com>,
        Samuel Holland <samuel@sholland.org>,
        Thomas Zimmermann <tzimmermann@suse.de>,
        Daniel Vetter <daniel@ffwll.ch>, Emma Anholt <emma@anholt.net>,
        David Airlie <airlied@linux.ie>,
        Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
        Kevin Hilman <khilman@baylibre.com>,
        Neil Armstrong <narmstrong@baylibre.com>,
        linux-sunxi@lists.linux.dev, linux-kernel@vger.kernel.org,
        Phil Elwell <phil@raspberrypi.com>,
        Mateusz Kwiatkowski <kfyatek+publicgit@gmail.com>,
        linux-arm-kernel@lists.infradead.org,
        Geert Uytterhoeven <geert@linux-m68k.org>,
        Dave Stevenson <dave.stevenson@raspberrypi.com>,
        linux-amlogic@lists.infradead.org, dri-devel@lists.freedesktop.org,
        Dom Cobley <dom@raspberrypi.com>
Subject: Re: [PATCH v1 05/35] drm/connector: Add TV standard property
Message-ID: <20220818153101.c25x33vkl6qboswe@houat>
References: <20220728-rpi-analog-tv-properties-v1-5-3d53ae722097@cerno.tech>
 <9fdecae2-80ad-6212-0522-7dccf9fb57be@tronnes.org>
 <20220816082612.grebxql5ynnfnvfd@houat>
 <ea6ebdda-f779-78af-1ffd-bd86d715077f@tronnes.org>
 <20220816094922.oqhrhefv327zo2ou@houat>
 <be9b6b71-fa2a-3290-2bce-901342e01981@tronnes.org>
 <20220817114605.jpb3tlnoseyvf65d@houat>
 <30f3005d-0acc-e5af-10ca-cf46f18b3478@tronnes.org>
 <133c2a1d-0b4c-cef9-11fe-9ce9985253d6@tronnes.org>
 <9daca9bf-838e-c3eb-51de-1cf5188a9341@tronnes.org>
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On Thu, Aug 18, 2022 at 05:01:38PM +0200, Noralf Tr=F8nnes wrote:
>=20
>=20
> Den 18.08.2022 01.23, skrev Noralf Tr=F8nnes:
> >=20
> >=20
> > Den 17.08.2022 15.11, skrev Noralf Tr=F8nnes:
> >>
> >>
> >> Den 17.08.2022 13.46, skrev Maxime Ripard:
> >>> On Tue, Aug 16, 2022 at 09:35:24PM +0200, Noralf Tr=F8nnes wrote:
> >>>> Den 16.08.2022 11.49, skrev Maxime Ripard:
> >>>>> On Tue, Aug 16, 2022 at 11:42:20AM +0200, Noralf Tr=F8nnes wrote:
> >>>>>> Den 16.08.2022 10.26, skrev Maxime Ripard:
> >>>>>>> Hi,
> >>>>>>>
> >>>>>>> On Mon, Aug 08, 2022 at 02:44:56PM +0200, Noralf Tr=F8nnes wrote:
> >>>>>>>> Den 29.07.2022 18.34, skrev Maxime Ripard:
> >>>>>>>>> The TV mode property has been around for a while now to select =
and get the
> >>>>>>>>> current TV mode output on an analog TV connector.
> >>>>>>>>>
> >>>>>>>>> Despite that property name being generic, its content isn't and=
 has been
> >>>>>>>>> driver-specific which makes it hard to build any generic behavi=
our on top
> >>>>>>>>> of it, both in kernel and user-space.
> >>>>>>>>>
> >>>>>>>>> Let's create a new bitmask tv norm property, that can contain a=
ny of the
> >>>>>>>>> analog TV standards currently supported by kernel drivers. Each=
 driver can
> >>>>>>>>> then pass in a bitmask of the modes it supports.
> >>>>>>>>>
> >>>>>>>>> We'll then be able to phase out the older tv mode property.
> >>>>>>>>>
> >>>>>>>>> Signed-off-by: Maxime Ripard <maxime@cerno.tech>
> >>>>>>>>>
> >=20
> >>>> How do you test the property? I've used modetest but I can only chan=
ge
> >>>> to a tv.mode that matches the current display mode. I can't switch f=
rom
> >>>> ntsc to pal for instance.
> >>>
> >>> Yep, if you want to change from PAL to NTSC, it will require a new mo=
de.
> >>>
> >>
> >> So userspace has to check tv.mode first and then create a display mode
> >> the driver will accept if switching to a different display mode is
> >> necessary? In other words, userspace can't discover from the kernel
> >> which display modes a certain tv.mode/norm provides before it is
> >> selected? If so, maybe libdrm should have some function(s) to deal with
> >> switching between modes that require a different display mode since
> >> knowledge about which display modes a tv.mode supports is needed before
> >> hand.
> >>
> >=20
> > I haven't used vc4 on Pi4 in mainline before and have finally gotten it
> > to work.
> >=20
> > I see that the connector reports 2 modes that together fit all tv.norms
> > so userspace doesn't have to contruct a display mode, but it does need
> > to know which display mode belongs to a certain tv.norm.
> >=20
> > When I try to use modetest I'm unable to set a mode:
> >=20
> > pi@pi4t:~ $ modetest -M vc4 -s 45:720x480i
> > setting mode 720x480i-29.97Hz on connectors 45, crtc 68
> > failed to set mode: Function not implemented
> >=20
> > The errno is misleading, modetest does a drmModeDirtyFB before checking
> > the error returned by drmModeSetCrtc.
> >=20
> > Setting the property succeeds, but the modeset still fails:
> >=20
> > pi@pi4t:~ $ modetest -M vc4 -s 45:720x480i -w 45:"tv norm":2
> > setting mode 720x480i-29.97Hz on connectors 45, crtc 68
> > failed to set mode: Function not implemented
> >=20
> > pi@pi4t:~ $ modetest -M vc4 -c
> >         37 tv norm:
> >                 flags: bitmask
> >                 values: NTSC-443=3D0x1 NTSC-J=3D0x2 NTSC-M=3D0x4 PAL-B=
=3D0x10
> > PAL-M=3D0x200 PAL-N=3D0x400 SECAM-B=3D0x2000
> >                 value: 2
> >=20
> > Here's the log, can you see if there's anything obvious in there:
> > https://gist.github.com/notro/a079498bf6b64327105752b2bafa8858
> >=20
>=20
> I'm one step closer as I now have fbcon working, I had forgotten to add
> enable_tvout=3D1 and I had disable_fw_kms_setup=3D1 which disables the
> video=3D mode on the kernel commandline.
>=20
> modetest still fails though, after alot of printk sprinkling, I've
> tracked it down to the drm_mode_equal test in
> drm_atomic_helper_connector_tv_check(). The aspect ratios differ:
>=20
> [   61.336295] drm_atomic_helper_connector_tv_check:
> mode->picture_aspect_ratio=3D1
> [   61.336301] drm_atomic_helper_connector_tv_check:
> &crtc_state->mode->picture_aspect_ratio=3D0

I haven't seen this when testing, but I'll have a look, thanks!
Maxime

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