Re: [PATCH v9 0/5] Add support for iMX8MQ Display Controller Subsystem

[Lucas Stach]

Hi Laurentiu,

On Fr, 2020-08-28 at 11:36 +0300, Laurentiu Palcu wrote:
> Hi Lucas,
> 
> I was wondering about the plans to merge this series. Since not many
> people can test it properly due to lack of DCSS support in the upstream
> NWL driver (which I heard it's coming soon) and a completely nonexistent
> HDP driver, are we going to take a leap of faith and merge it as is? Or
> should we wait?

I think even if the bridges aren't ready yet, the driver is in a good
enough shape to merge it. There's no point in letting it accumulate
bitrot while waiting for the bridges to land. Also I guess it will make
bridge driver development a lot easier when the DCSS driver is in-tree.

> As to who is going to do the actual merge, I know we had a brief
> discussion about it some time ago and I was supposed to apply for
> drm-misc rights, however it feels a little awkward to merge my own
> code... :) Though, I might not even qualify for drm-misc rights anyway,
> considering I haven't been very active in this area... :/

Please consider applying for drm-misc merge rights. Even if you don't
do the initial merge I think it will come in handy in the long run.

> On that note, I will probably need help with the merging, provided it's
> still happenning. Will you be able to help me out with this?

Sure, I'm having some time available this week. I'll give this v9
another spin on my boards and will do the merge after that.

Regards,
Lucas

> Thanks,
> laurentiu
> 
> On Fri, Jul 31, 2020 at 11:18:28AM +0300, Laurentiu Palcu wrote:
> > From: Laurentiu Palcu <laurentiu.palcu@xxxxxxx>
> > 
> > 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).
> > 
> > Thanks,
> > Laurentiu
> > 
> > Changes in v9:
> >  * Fixed a compilation issue found by Guido in his setup: 'select
> >    VIDEOMODE_HELPERS' was missing from Kconfig;
> >  * Use imx8mq-clock.h in the bindings file so one can understand what
> >    those clock values mean;
> >  * no other changes done. Couldn't address the hang Guido reported as
> >    it's not happening in my setup. However, in my tree, there are some
> >    extra NWL and ADV patches applied on top of upstream ones... Also,
> >    removing them and testing only with upstream, even if there's no
> >    image out, does not produce a hang... :/
> > 
> > Changes in v8:
> >  * Removed 'select RESET_CONTROLLER" from Kconfig as Philipp pointed
> >    out. SRC is not used in DCSS driver;
> >  * Nothing else changed;
> > 
> > Changes in v7:
> >  * Added a patch to initialize the connector using the drm_bridge_connector
> >    API as Sam suggested. Tested it using NWL_DSI and ADV7535 with
> >    Guido's patch [1] applied and one fix for ADV [2]. Also, some extra
> >    patches for ADV and NWL were needed, from our downstream tree, which
> >    will be upstreamed soon by their author;
> >  * Rest of the patches are untouched;
> > 
> > [1] https://lists.freedesktop.org/archives/dri-devel/2020-July/273025.html
> > [2] https://lists.freedesktop.org/archives/dri-devel/2020-July/273132.html
> > 
> > Changes in v6:
> >  * Addressed Rob's comment and added "additionalProperties: false" at
> >    the end of the bindings' properties. However, this change surfaced
> >    an issue with the assigned-clock* properties not being documented in
> >    the properties section. Added the descriptions and the bindings patch
> >    will need another review;
> >  * Added an entry for DCSS driver in the MAINTAINERS file;
> >  * Removed the component framework patch altogether;
> > 
> > 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: use drm_bridge_connector API
> >   MAINTAINERS: Add entry for i.MX 8MQ DCSS driver
> >   dt-bindings: display: imx: add bindings for DCSS
> > 
> >  .../bindings/display/imx/nxp,imx8mq-dcss.yaml | 108 +++
> >  MAINTAINERS                                   |   8 +
> >  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           | 325 +++++++
> >  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           | 138 +++
> >  drivers/gpu/drm/imx/dcss/dcss-dtg.c           | 409 +++++++++
> >  drivers/gpu/drm/imx/dcss/dcss-kms.c           | 198 +++++
> >  drivers/gpu/drm/imx/dcss/dcss-kms.h           |  44 +
> >  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, 4112 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
> > 
> > -- 
> > 2.23.0
> >