Re: [PATCH v5 0/4] Add support for iMX8MQ Display Controller Subsystem

[Lucas Stach <l.stach@pengutronix.de>]

Hi Laurentiu,

Am Donnerstag, den 09.07.2020, 19:47 +0300 schrieb Laurentiu Palcu:
> From: Laurentiu Palcu <laurentiu.palcu@nxp.com>
> 
> Hi,
> 
> This patchset adds initial DCSS support for iMX8MQ chip. Initial support
> includes only graphics plane support (no video planes), no HDR10 capabilities,
> no graphics decompression (only linear, tiled and super-tiled buffers allowed).
> 
> Support for the rest of the features will be added incrementally, in subsequent
> patches.
> 
> The patchset was tested with both HDP driver (in the downstream tree) and the upstream
> MIPI-DSI driver (with a couple of patches on top, to make it work correctly with DCSS).

I think the series (minus 3/5 and minor correction to the DT binding)
is fine to go in now. So just some formal questions: are you going to
maintain this driver in upstream? If so we should add a MAINTAINERS
entry to that effect. I can offer to act as a reviewer in this case.

How do you intend to merge this? IMO pushing this through drm-misc
seems like the right thing to do. If you agree I can help you get this
applied. If you are going to maintain the driver on your own, I think
you should then apply for commit rights to drm-misc.

Regards,
Lucas

> Thanks,
> Laurentiu
> 
> Changes in v5:
>  * Rebased to latest;
>  * Took out component framework support and made it a separate patch so
>    that people can still test with HDP driver, which makes use of it.
>    But the idea is to get rid of it once HDP driver's next versions
>    will remove component framework as well;
>  * Slight improvement to modesetting: avoid cutting off the pixel clock
>    if the new mode and the old one are equal. Also, in this case, is
>    not necessary to wait for DTG to shut off. This would allow to switch
>    from 8b RGB to 12b YUV422, for example, with no interruptions (at least
>    from DCSS point of view);
>  * Do not fire off CTXLD when going to suspend, unless it still has
>    entries that need to be committed to DCSS;
>  * Addressed Rob's comments on bindings;
> 
> Changes in v4:
>  * Addressed Lucas and Philipp's comments:
>    * Added DRM_KMS_CMA_HELPER dependency in Kconfig;
>    * Removed usage of devm_ functions since I'm already doing all the
>      clean-up in the submodules_deinit();
>    * Moved the drm_crtc_arm_vblank_event() in dcss_crtc_atomic_flush();
>    * Removed en_completion variable from dcss_crtc since this was
>      introduced mainly to avoid vblank timeout warnings which were fixed
>      by arming the vblank event in flush() instead of begin();
>    * Removed clks_on and irq_enabled flags since all the calls to
>      enabling/disabling clocks and interrupts were balanced;
>    * Removed the custom atomic_commit callback and used the DRM core
>      helper and, in the process, got rid of a workqueue that wasn't
>      necessary anymore;
>    * Fixed some minor DT binding issues flagged by Philipp;
>    * Some other minor changes suggested by Lucas;
>  * Removed YUV formats from the supported formats as these cannot work
>    without the HDR10 module CSCs and LUTs. Will add them back when I
>    will add support for video planes;
> 
> Changes in v3:
>  * rebased to latest linux-next and made it compile as drmP.h was
>    removed;
>  * removed the patch adding the VIDEO2_PLL clock. It's already applied;
>  * removed an unnecessary 50ms sleep in the dcss_dtg_sync_set();
>  * fixed a a spurious hang reported by Lukas Hartmann and encountered
>    by me several times;
>  * mask DPR and DTG interrupts by default, as they may come enabled from
>    U-boot;
> 
> Changes in v2:
>  * Removed '0x' in node's unit-address both in DT and yaml;
>  * Made the address region size lowercase, to be consistent;
>  * Removed some left-over references to P010;
>  * Added a Kconfig dependency of DRM && ARCH_MXC. This will also silence compilation
>    issues reported by kbuild for other architectures;
> 
> Laurentiu Palcu (5):
>   drm/imx: compile imx directory by default
>   drm/imx: Add initial support for DCSS on iMX8MQ
>   drm/imx/dcss: add component framework functionality
>   dt-bindings: display: imx: add bindings for DCSS
>   arm64: dts: imx8mq: add DCSS node
> 
>  .../bindings/display/imx/nxp,imx8mq-dcss.yaml |  84 ++
>  arch/arm64/boot/dts/freescale/imx8mq.dtsi     |  23 +
>  drivers/gpu/drm/Makefile                      |   2 +-
>  drivers/gpu/drm/imx/Kconfig                   |   2 +
>  drivers/gpu/drm/imx/Makefile                  |   1 +
>  drivers/gpu/drm/imx/dcss/Kconfig              |   9 +
>  drivers/gpu/drm/imx/dcss/Makefile             |   6 +
>  drivers/gpu/drm/imx/dcss/dcss-blkctl.c        |  70 ++
>  drivers/gpu/drm/imx/dcss/dcss-crtc.c          | 219 +++++
>  drivers/gpu/drm/imx/dcss/dcss-ctxld.c         | 424 +++++++++
>  drivers/gpu/drm/imx/dcss/dcss-dev.c           | 314 +++++++
>  drivers/gpu/drm/imx/dcss/dcss-dev.h           | 177 ++++
>  drivers/gpu/drm/imx/dcss/dcss-dpr.c           | 562 ++++++++++++
>  drivers/gpu/drm/imx/dcss/dcss-drv.c           | 183 ++++
>  drivers/gpu/drm/imx/dcss/dcss-dtg.c           | 409 +++++++++
>  drivers/gpu/drm/imx/dcss/dcss-kms.c           | 185 ++++
>  drivers/gpu/drm/imx/dcss/dcss-kms.h           |  43 +
>  drivers/gpu/drm/imx/dcss/dcss-plane.c         | 405 +++++++++
>  drivers/gpu/drm/imx/dcss/dcss-scaler.c        | 826 ++++++++++++++++++
>  drivers/gpu/drm/imx/dcss/dcss-ss.c            | 180 ++++
>  20 files changed, 4123 insertions(+), 1 deletion(-)
>  create mode 100644 Documentation/devicetree/bindings/display/imx/nxp,imx8mq-dcss.yaml
>  create mode 100644 drivers/gpu/drm/imx/dcss/Kconfig
>  create mode 100644 drivers/gpu/drm/imx/dcss/Makefile
>  create mode 100644 drivers/gpu/drm/imx/dcss/dcss-blkctl.c
>  create mode 100644 drivers/gpu/drm/imx/dcss/dcss-crtc.c
>  create mode 100644 drivers/gpu/drm/imx/dcss/dcss-ctxld.c
>  create mode 100644 drivers/gpu/drm/imx/dcss/dcss-dev.c
>  create mode 100644 drivers/gpu/drm/imx/dcss/dcss-dev.h
>  create mode 100644 drivers/gpu/drm/imx/dcss/dcss-dpr.c
>  create mode 100644 drivers/gpu/drm/imx/dcss/dcss-drv.c
>  create mode 100644 drivers/gpu/drm/imx/dcss/dcss-dtg.c
>  create mode 100644 drivers/gpu/drm/imx/dcss/dcss-kms.c
>  create mode 100644 drivers/gpu/drm/imx/dcss/dcss-kms.h
>  create mode 100644 drivers/gpu/drm/imx/dcss/dcss-plane.c
>  create mode 100644 drivers/gpu/drm/imx/dcss/dcss-scaler.c
>  create mode 100644 drivers/gpu/drm/imx/dcss/dcss-ss.c
>