Hi,
On Thu, Sep 22, 2022 at 04:25:17PM +0200, Maxime Ripard wrote:
> 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 mode 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.
>
> One can switch from NTSC to PAL now using (on vc4)
>
> modetest -M vc4 -s 53:720x480i -w 53:'TV mode':1 # NTSC
> modetest -M vc4 -s 53:720x576i -w 53:'TV mode':4 # PAL
>
> Let me know what you think,
> Maxime
>
> To: David Airlie <[email protected]>
> To: Daniel Vetter <[email protected]>
> To: Maarten Lankhorst <[email protected]>
> To: Maxime Ripard <[email protected]>
> To: Thomas Zimmermann <[email protected]>
> To: Emma Anholt <[email protected]>
> To: Jani Nikula <[email protected]>
> To: Joonas Lahtinen <[email protected]>
> To: Rodrigo Vivi <[email protected]>
> To: Tvrtko Ursulin <[email protected]>
> To: Ben Skeggs <[email protected]>
> To: Karol Herbst <[email protected]>
> To: Lyude Paul <[email protected]>
> To: Chen-Yu Tsai <[email protected]>
> To: Jernej Skrabec <[email protected]>
> To: Samuel Holland <[email protected]>
> Cc: Geert Uytterhoeven <[email protected]>
> Cc: Mateusz Kwiatkowski <[email protected]>
> Cc: "Noralf Tr?nnes" <[email protected]>
> Cc: Dave Stevenson <[email protected]>
> Cc: Dom Cobley <[email protected]>
> Cc: Phil Elwell <[email protected]>
> Cc: <[email protected]>
> Cc: [email protected]
> Cc: [email protected]
> Cc: [email protected]
> Cc: [email protected]
> Cc: [email protected]
> Cc: Hans de Goede <[email protected]>
> Signed-off-by: Maxime Ripard <[email protected]>
>
> ---
> Changes in v3:
> - Applied some of the fixes to vc4 and sun4i
> - Renamed the old TV mode property to legacy_mode
> - Fixed a bunch of bisection errors
> - Removed most of the redundant TV modes
> - Added a new None TV mode to not fall back on NTSC by mistake
> - Fixed the mode generation function to match better what is expected
> - Added some logging to the mode generation function
> - Split the improvements to the named mode parsing logic into separate patches
> - Added more checks to the TV atomic_check helper
> - Link to v2: https://lore.kernel.org/dri-devel/[email protected]/
Sorry, this is obviously the v3...
Maxime