[PATCH v1 00/35] drm: Analog TV Improvements

[Mateusz Kwiatkowski]

Hi Maxime,

I tried testing and reviewing your changes properly over the last weekend, but
ultimately ran into this ("flip_done timed out" etc.) issue and was unable to
mitigate it, at least so far. This seems to pop up every time I try to change
modes in any way (either change the TV norm, or just try doing
"xrandr --output Composite-1 --off" followed by bringing it back on; it also
means that the Pi goes unusable when the DE's screen saving routine kicks in).

I'm using a Pi 4, and it works with the rpi-5.13.y branch
https://github.com/raspberrypi/linux, but seemingly nothing newer.
I specifically tried rpi-5.14.y, rpi-5.15.y and rpi-5.19.y - rpi-5.15.y,
which is the current main branch in Raspberry Pi OS, seems to be broken since
forever; at least since my patches (originally written for 5.10) landed there.

I'll try identifying the issue further, possibly later today, and maybe check
the rpi-6.0.y branch as well.

Best regards,
Mateusz Kwiatkowski

W dniu 22.08.2022 o 09:48, Maxime Ripard pisze:
> Hi,
>
> On Sun, Aug 21, 2022 at 06:33:12PM +0200, Noralf Trønnes wrote:
>> Den 29.07.2022 18.34, skrev Maxime Ripard:
>>> Hi,
>>>
>>> Here's a series aiming at improving the command line named modes support,
>>> and more importantly how we deal with all the analog TV variants.
>>>
>>> The named modes support were initially introduced to allow to specify the
>>> analog TV mode to be used.
>>>
>>> However, this was causing multiple issues:
>>>
>>>   * The mode name parsed on the command line was passed directly to the
>>>     driver, which had to figure out which mode it was suppose to match;
>>>
>>>   * Figuring that out wasn't really easy, since the video= argument or what
>>>     the userspace might not even have a name in the first place, but
>>>     instead could have passed a mode with the same timings;
>>>
>>>   * The fallback to matching on the timings was mostly working as long as
>>>     we were supporting one 525 lines (most likely NSTC) and one 625 lines
>>>     (PAL), but couldn't differentiate between two modes with the same
>>>     timings (NTSC vs PAL-M vs NSTC-J for example); 
>>>
>>>   * There was also some overlap with the tv mode property registered by 
>>>     drm_mode_create_tv_properties(), but named modes weren't interacting
>>>     with that property at all.
>>>
>>>   * Even though that property was generic, its possible values were
>>>     specific to each drivers, which made some generic support difficult.
>>>
>>> Thus, I chose to tackle in multiple steps:
>>>
>>>   * A new TV norm property was introduced, with generic values, each driver
>>>     reporting through a bitmask what standard it supports to the userspace;
>>>
>>>   * This option was added to the command line parsing code to be able to
>>>     specify it on the kernel command line, and new atomic_check and reset
>>>     helpers were created to integrate properly into atomic KMS;
>>>
>>>   * The named mode parsing code is now creating a proper display mode for
>>>     the given named mode, and the TV standard will thus be part of the
>>>     connector state;
>>>
>>>   * Two drivers were converted and tested for now (vc4 and sun4i), with
>>>     some backward compatibility code to translate the old TV mode to the
>>>     new TV mode;
>>>
>>> Unit tests were created along the way. Nouveau, ch7006 and gud are
>>> currently broken for now since I expect that work to be reworked fairly
>>> significantly. I'm also not entirely sure about how to migrate GUD to the
>>> new property.
>>>
>>> Let me know what you think,
>>> Maxime
>>>
>> I don't know if it's related to this patchset or not, but I do get this:
>>
>> pi at pi4t:~ $ sudo dmesg -C && sudo modprobe -r vc4 && sudo modprobe vc4
>> && dmesg
>> [  430.066211] Console: switching to colour dummy device 80x30
>> [  431.294788] vc4-drm gpu: bound fe400000.hvs (ops vc4_hvs_ops [vc4])
>> [  431.295115] vc4-drm gpu: bound fec13000.vec (ops vc4_vec_ops [vc4])
>> [  431.295467] vc4-drm gpu: bound fe004000.txp (ops vc4_txp_ops [vc4])
>> [  431.295804] vc4-drm gpu: bound fec12000.pixelvalve (ops vc4_crtc_ops
>> [vc4])
>> [  431.298895] [drm] Initialized vc4 0.0.0 20140616 for gpu on minor 0
>> [  441.444250] vc4-drm gpu: [drm] *ERROR* [CRTC:68:crtc-1] flip_done
>> timed out
>> [  441.446529] Console: switching to colour frame buffer device 90x30
>> [  451.684321] vc4-drm gpu: [drm] *ERROR* flip_done timed out
>> [  451.684347] vc4-drm gpu: [drm] *ERROR* [CRTC:68:crtc-1] commit wait
>> timed out
>> [  461.924255] vc4-drm gpu: [drm] *ERROR* flip_done timed out
>> [  461.924281] vc4-drm gpu: [drm] *ERROR* [CONNECTOR:45:Composite-1]
>> commit wait timed out
>> [  472.164006] vc4-drm gpu: [drm] *ERROR* flip_done timed out
>> [  472.164031] vc4-drm gpu: [drm] *ERROR* [PLANE:61:plane-1] commit wait
>> timed out
>> [  482.403877] vc4-drm gpu: [drm] *ERROR* flip_done timed out
>> [  482.403903] vc4-drm gpu: [drm] *ERROR* Timed out waiting for commit
>> [  492.643799] vc4-drm gpu: [drm] *ERROR* [CRTC:68:crtc-1] flip_done
>> timed out
>> [  492.647073] vc4-drm gpu: [drm] fb0: vc4drmfb frame buffer device
> Module unloading/reloading has been janky for a while.
>
> I've fixed it up recently but it doesn't surprise me that there's still
> some situation that won't work. Is it on a Pi3?
>
> Maxime